kbuild: remove all dummy assignments to obj-

Now kbuild core scripts create empty built-in.o where necessary.
Remove "obj- := dummy.o" tricks.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

arch/arm/mach-uniphier/Makefile

-obj- += dummy.o

arch/mips/boot/dts/brcm/Makefile

@@ -35,6 +35,3 @@ dtb-$(CONFIG_DT_NONE) += \
 	bcm97435svmb.dtb
 
 obj-y				+= $(patsubst %.dtb, %.dtb.o, $(dtb-y))
-
-# Force kbuild to make empty built-in.o if necessary
-obj-				+= dummy.o

arch/mips/boot/dts/cavium-octeon/Makefile

@@ -2,6 +2,3 @@
 dtb-$(CONFIG_CAVIUM_OCTEON_SOC)	+= octeon_3xxx.dtb octeon_68xx.dtb
 
 obj-y				+= $(patsubst %.dtb, %.dtb.o, $(dtb-y))
-
-# Force kbuild to make empty built-in.o if necessary
-obj-				+= dummy.o

arch/mips/boot/dts/img/Makefile

@@ -3,6 +3,3 @@ dtb-$(CONFIG_FIT_IMAGE_FDT_BOSTON)	+= boston.dtb
 
 dtb-$(CONFIG_MACH_PISTACHIO)	+= pistachio_marduk.dtb
 obj-$(CONFIG_MACH_PISTACHIO)	+= pistachio_marduk.dtb.o
-
-# Force kbuild to make empty built-in.o if necessary
-obj-				+= dummy.o

arch/mips/boot/dts/ingenic/Makefile

@@ -3,6 +3,3 @@ dtb-$(CONFIG_JZ4740_QI_LB60)	+= qi_lb60.dtb
 dtb-$(CONFIG_JZ4780_CI20)	+= ci20.dtb
 
 obj-y				+= $(patsubst %.dtb, %.dtb.o, $(dtb-y))
-
-# Force kbuild to make empty built-in.o if necessary
-obj-				+= dummy.o

arch/mips/boot/dts/lantiq/Makefile

@@ -2,6 +2,3 @@
 dtb-$(CONFIG_DT_EASY50712)	+= easy50712.dtb
 
 obj-y				+= $(patsubst %.dtb, %.dtb.o, $(dtb-y))
-
-# Force kbuild to make empty built-in.o if necessary
-obj-				+= dummy.o

arch/mips/boot/dts/mti/Makefile

@@ -3,6 +3,3 @@ dtb-$(CONFIG_MIPS_MALTA)	+= malta.dtb
 dtb-$(CONFIG_LEGACY_BOARD_SEAD3)	+= sead3.dtb
 
 obj-y				+= $(patsubst %.dtb, %.dtb.o, $(dtb-y))
-
-# Force kbuild to make empty built-in.o if necessary
-obj-				+= dummy.o

arch/mips/boot/dts/netlogic/Makefile

@@ -6,6 +6,3 @@ dtb-$(CONFIG_DT_XLP_GVP)	+= xlp_gvp.dtb
 dtb-$(CONFIG_DT_XLP_RVP)	+= xlp_rvp.dtb
 
 obj-y				+= $(patsubst %.dtb, %.dtb.o, $(dtb-y))
-
-# Force kbuild to make empty built-in.o if necessary
-obj-				+= dummy.o

arch/mips/boot/dts/ni/Makefile

 dtb-$(CONFIG_FIT_IMAGE_FDT_NI169445)	+= 169445.dtb
-
-# Force kbuild to make empty built-in.o if necessary
-obj-					+= dummy.o

arch/mips/boot/dts/pic32/Makefile

@@ -5,6 +5,3 @@ dtb-$(CONFIG_DTB_PIC32_NONE)		+= \
 					pic32mzda_sk.dtb
 
 obj-y				+= $(patsubst %.dtb, %.dtb.o, $(dtb-y))
-
-# Force kbuild to make empty built-in.o if necessary
-obj-				+= dummy.o

arch/mips/boot/dts/qca/Makefile

@@ -5,6 +5,3 @@ dtb-$(CONFIG_ATH79)			+= ar9331_dpt_module.dtb
 dtb-$(CONFIG_ATH79)			+= ar9331_dragino_ms14.dtb
 dtb-$(CONFIG_ATH79)			+= ar9331_omega.dtb
 dtb-$(CONFIG_ATH79)			+= ar9331_tl_mr3020.dtb
-
-# Force kbuild to make empty built-in.o if necessary
-obj-				+= dummy.o

arch/mips/boot/dts/ralink/Makefile

@@ -7,6 +7,3 @@ dtb-$(CONFIG_DTB_OMEGA2P)	+= omega2p.dtb
 dtb-$(CONFIG_DTB_VOCORE2)	+= vocore2.dtb
 
 obj-y				+= $(patsubst %.dtb, %.dtb.o, $(dtb-y))
-
-# Force kbuild to make empty built-in.o if necessary
-obj-				+= dummy.o

arch/mips/boot/dts/xilfpga/Makefile

@@ -2,6 +2,3 @@
 dtb-$(CONFIG_FIT_IMAGE_FDT_XILFPGA)	+= nexys4ddr.dtb
 
 obj-y				+= $(patsubst %.dtb, %.dtb.o, $(dtb-y))
-
-# Force kbuild to make empty built-in.o if necessary
-obj-				+= dummy.o

firmware/Makefile

@@ -59,6 +59,3 @@ endif
 
 targets := $(patsubst $(obj)/%,%, \
                                 $(shell find $(obj) -name \*.gen.S 2>/dev/null))
-# Without this, built-in.o won't be created when it's empty, and the
-# final vmlinux link will fail.
-obj- := dummy

samples/bpf/Makefile

 # SPDX-License-Identifier: GPL-2.0
-# kbuild trick to avoid linker error. Can be omitted if a module is built.
-obj- := dummy.o
-
 # List of programs to build
 hostprogs-y := test_lru_dist
 hostprogs-y += sock_example

samples/hidraw/Makefile

 # SPDX-License-Identifier: GPL-2.0
-# kbuild trick to avoid linker error. Can be omitted if a module is built.
-obj- := dummy.o
-
 # List of programs to build
 hostprogs-y := hid-example
 

samples/seccomp/Makefile

 # SPDX-License-Identifier: GPL-2.0
-# kbuild trick to avoid linker error. Can be omitted if a module is built.
-obj- := dummy.o
-
 hostprogs-$(CONFIG_SAMPLE_SECCOMP) := bpf-fancy dropper bpf-direct
 
 HOSTCFLAGS_bpf-fancy.o += -I$(objtree)/usr/include

samples/sockmap/Makefile

-# kbuild trick to avoid linker error. Can be omitted if a module is built.
-obj- := dummy.o
-
 # List of programs to build
 hostprogs-y := sockmap
 

samples/statx/Makefile

-# kbuild trick to avoid linker error. Can be omitted if a module is built.
-obj- := dummy.o
-
 # List of programs to build
 hostprogs-$(CONFIG_SAMPLE_STATX) := test-statx
 

samples/uhid/Makefile

-# kbuild trick to avoid linker error. Can be omitted if a module is built.
-obj- := dummy.o
-
 # List of programs to build
 hostprogs-y := uhid-example