post: Remove <common.h> and add needed includes

Remove <common.h> from all "post/" files and when needed add
missing include files directly.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/post/post.c b/post/post.c
index 946d909..705f94c 100644
--- a/post/post.c
+++ b/post/post.c
@@ -4,7 +4,7 @@
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  */
 
-#include <common.h>
+#include <config.h>
 #include <bootstage.h>
 #include <env.h>
 #include <log.h>