post: Migrate to Kconfig

We move the existing CONFIG_POST_* functionality over to CFG_POST and
then introduce CONFIG_POST to Kconfig.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/post/lib_powerpc/complex.c b/post/lib_powerpc/complex.c
index bb29e91..d2ec21b 100644
--- a/post/lib_powerpc/complex.c
+++ b/post/lib_powerpc/complex.c
@@ -18,7 +18,7 @@
 #include <post.h>
 #include "cpu_asm.h"
 
-#if CONFIG_POST & CONFIG_SYS_POST_CPU
+#if CFG_POST & CONFIG_SYS_POST_CPU
 
 extern int cpu_post_complex_1_asm (int a1, int a2, int a3, int a4, int n);
 extern int cpu_post_complex_2_asm (int x, int n);