kbuild: refactor part-of-module

Use $(foreach ...) to make it shorter.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

scripts/Makefile.build

@@ -94,17 +94,15 @@ endif
 # ---------------------------------------------------------------------------
 
 # Default is built-in, unless we know otherwise
+$(foreach x, i lst o s, $(patsubst %.o,%.$(x),$(real-obj-m))): \
+	part-of-module := y
+
 modkern_cflags =                                          \
 	$(if $(part-of-module),                           \
 		$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
 		$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
 quiet_modtag = $(if $(part-of-module),[M],   )
 
-$(real-obj-m)        : part-of-module := y
-$(real-obj-m:.o=.i)  : part-of-module := y
-$(real-obj-m:.o=.s)  : part-of-module := y
-$(real-obj-m:.o=.lst): part-of-module := y
-
 quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
 cmd_cc_s_c       = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<