treewide: Make arch-specific bootm code depend on BOOTM

Allow these functions to be compiled in when CONFIG_BOOTM is enabled,
even if CONFIG_CMD_BOOTM is not.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Angelo Dureghello <angelo@kernel-space.org>
diff --git a/arch/m68k/lib/Makefile b/arch/m68k/lib/Makefile
index 6e1fd93..5ccd954 100644
--- a/arch/m68k/lib/Makefile
+++ b/arch/m68k/lib/Makefile
@@ -8,7 +8,7 @@
 lib-$(CONFIG_USE_PRIVATE_LIBGCC) += lshrdi3.o muldi3.o ashldi3.o ashrdi3.o
 
 obj-y	+= bdinfo.o
-obj-$(CONFIG_CMD_BOOTM) += bootm.o
+obj-$(CONFIG_BOOTM) += bootm.o
 obj-y	+= cache.o
 obj-y	+= interrupts.o
 obj-y	+= time.o