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/fpu/20001122-1.c b/post/lib_powerpc/fpu/20001122-1.c
index 4b452dc..eddd3f9 100644
--- a/post/lib_powerpc/fpu/20001122-1.c
+++ b/post/lib_powerpc/fpu/20001122-1.c
@@ -13,7 +13,7 @@
 
 GNU_FPOST_ATTR
 
-#if CONFIG_POST & CONFIG_SYS_POST_FPU
+#if CFG_POST & CONFIG_SYS_POST_FPU
 
 int fpu_post_test_math1 (void)
 {
@@ -40,4 +40,4 @@
 	return 0;
 }
 
-#endif /* CONFIG_POST & CONFIG_SYS_POST_FPU */
+#endif /* CFG_POST & CONFIG_SYS_POST_FPU */