Blackfin: post: generalize led/button tests with GPIOs

Make it easy for any Blackfin board to enable led/push button tests.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/arch/blackfin/lib/Makefile b/arch/blackfin/lib/Makefile
index 18c9f74..37e0663 100644
--- a/arch/blackfin/lib/Makefile
+++ b/arch/blackfin/lib/Makefile
@@ -46,6 +46,7 @@
 COBJS-$(CONFIG_CMD_CACHE_DUMP) += cmd_cache_dump.o
 COBJS-$(CONFIG_CMD_KGDB) += kgdb.o
 COBJS-y	+= muldi3.o
+COBJS-$(CONFIG_HAS_POST) += post.o
 COBJS-y	+= string.o
 
 SRCS	:= $(SOBJS-y:.o=.S) $(COBJS-y:.o=.c)