post: Move CONFIG_SYS_POST to CFG_SYS_POST

Migrate the rest of the CONFIG_SYS_POST macros over to CFG_SYS_POST
namespace.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/post/lib_powerpc/string.c b/post/lib_powerpc/string.c
index 9b54847..21e02bc 100644
--- a/post/lib_powerpc/string.c
+++ b/post/lib_powerpc/string.c
@@ -20,7 +20,7 @@
 #include <post.h>
 #include "cpu_asm.h"
 
-#if CFG_POST & CONFIG_SYS_POST_CPU
+#if CFG_POST & CFG_SYS_POST_CPU
 
 extern void cpu_post_exec_02 (ulong *code, ulong op1, ulong op2);
 extern void cpu_post_exec_04 (ulong *code, ulong op1, ulong op2, ulong op3,