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/post.c b/post/post.c
index b81425d..9964b41 100644
--- a/post/post.c
+++ b/post/post.c
@@ -168,7 +168,7 @@
 	post_word_store(word);
 }
 
-#ifndef CONFIG_POST_SKIP_ENV_FLAGS
+#ifndef CFG_POST_SKIP_ENV_FLAGS
 static void post_get_env_flags(int *test_flags)
 {
 	int  flag[] = {  POST_POWERON,   POST_NORMAL,   POST_SLOWTEST,
@@ -227,7 +227,7 @@
 	for (j = 0; j < post_list_size; j++)
 		test_flags[j] = post_list[j].flags;
 
-#ifndef CONFIG_POST_SKIP_ENV_FLAGS
+#ifndef CFG_POST_SKIP_ENV_FLAGS
 	post_get_env_flags(test_flags);
 #endif