sparc: vdso: simplify obj-y addition

Add objects to obj-y in a more straightforward way.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>

arch/sparc/vdso/Makefile

@@ -3,9 +3,6 @@
 # Building vDSO images for sparc.
 #
 
-VDSO64-$(CONFIG_SPARC64)	:= y
-VDSOCOMPAT-$(CONFIG_COMPAT)	:= y
-
 # files to link into the vdso
 vobjs-y := vdso-note.o vclock_gettime.o
 
@@ -13,18 +10,14 @@ vobjs-y := vdso-note.o vclock_gettime.o
 obj-y				+= vma.o
 
 # vDSO images to build
-vdso_img-$(VDSO64-y)		+= 64
-vdso_img-$(VDSOCOMPAT-y)	+= 32
+obj-$(CONFIG_SPARC64)		+= vdso-image-64.o
+obj-$(CONFIG_COMPAT)		+= vdso-image-32.o
 
 vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
 
 $(obj)/vdso.o: $(obj)/vdso.so
 
 targets += vdso.lds $(vobjs-y)
-
-# Build the vDSO image C files and link them in.
-vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
-obj-y += $(vdso_img_objs)
 targets += $(foreach x, 32 64, vdso-image-$(x).c vdso$(x).so vdso$(x).so.dbg)
 
 CPPFLAGS_vdso.lds += -P -C