Makefile: Restrict system emulation and tools objects

Restrict all the system emulation and tools objects with a
Makefile IF (CONFIG_SOFTMMU OR CONFIG_TOOLS) check.

Using the same description over and over is not very helpful.
Use it once, just before the if() block.
Reviewed-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Message-Id: <20200118140619.26333-4-philmd@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Makefile.objs

@@ -4,15 +4,14 @@ stub-obj-y = stubs/
 util-obj-y = crypto/ util/ qobject/ qapi/
 qom-obj-y = qom/
 
-chardev-obj-y = chardev/
-
 #######################################################################
-# authz-obj-y is code used by both qemu system emulation and qemu-img
+# code used by both qemu system emulation and qemu-img
 
-authz-obj-y = authz/
+ifeq ($(call lor,$(CONFIG_SOFTMMU),$(CONFIG_TOOLS)),y)
 
-#######################################################################
-# block-obj-y is code used by both qemu system emulation and qemu-img
+chardev-obj-y = chardev/
+
+authz-obj-y = authz/
 
 block-obj-y = nbd/
 block-obj-y += block.o blockjob.o job.o
@@ -22,16 +21,12 @@ block-obj-$(CONFIG_REPLICATION) += replication.o
 
 block-obj-m = block/
 
-#######################################################################
-# crypto-obj-y is code used by both qemu system emulation and qemu-img
-
 crypto-obj-y = crypto/
 
-#######################################################################
-# io-obj-y is code used by both qemu system emulation and qemu-img
-
 io-obj-y = io/
 
+endif # CONFIG_SOFTMMU or CONFIG_TOOLS
+
 ######################################################################
 # Target independent part of system emulation. The long term path is to
 # suppress *all* target specific code in case of system emulation, i.e. a