common: Drop part.h from common header

Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/fs/ext4/ext4_write.c b/fs/ext4/ext4_write.c
index 67aeba1..ce1fddc 100644
--- a/fs/ext4/ext4_write.c
+++ b/fs/ext4/ext4_write.c
@@ -22,8 +22,10 @@
 
 
 #include <common.h>
+#include <blk.h>
 #include <malloc.h>
 #include <memalign.h>
+#include <part.h>
 #include <linux/stat.h>
 #include <div64.h>
 #include "ext4_common.h"