of: unittest: refactor Makefile

Some cleanups:
 - use obj-$(CONFIG_OF_OVERLAY) instead of ifdef ... endif
 - compute targets from obj-y

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Rob Herring <robh@kernel.org>

drivers/of/unittest-data/Makefile

@@ -2,19 +2,12 @@
 DTC_FLAGS_testcases := -Wno-interrupts_property
 obj-y += testcases.dtb.o
 
-targets += testcases.dtb testcases.dtb.S
+obj-$(CONFIG_OF_OVERLAY) += overlay.dtb.o \
+			    overlay_bad_phandle.dtb.o \
+			    overlay_bad_symbol.dtb.o \
+			    overlay_base.dtb.o
 
-ifdef CONFIG_OF_OVERLAY
-
-obj-y += overlay.dtb.o
-obj-y += overlay_bad_phandle.dtb.o
-obj-y += overlay_bad_symbol.dtb.o
-obj-y += overlay_base.dtb.o
-
-targets += overlay.dtb overlay.dtb.S
-targets += overlay_bad_phandle.dtb overlay_bad_phandle.dtb.S
-targets += overlay_bad_symbol.dtb overlay_bad_symbol.dtb.S
-targets += overlay_base.dtb overlay_base.dtb.S
+targets += $(foreach suffix, dtb dtb.S, $(patsubst %.dtb.o,%.$(suffix),$(obj-y)))
 
 # enable creation of __symbols__ node
 DTC_FLAGS_overlay := -@
@@ -22,8 +15,6 @@ DTC_FLAGS_overlay_bad_phandle := -@
 DTC_FLAGS_overlay_bad_symbol := -@
 DTC_FLAGS_overlay_base := -@
 
-endif
-
 .PRECIOUS: \
 	$(obj)/%.dtb.S \
 	$(obj)/%.dtb