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/sandbox/sandboxfs.c b/fs/sandbox/sandboxfs.c
index 5851fe2..4ae41d5 100644
--- a/fs/sandbox/sandboxfs.c
+++ b/fs/sandbox/sandboxfs.c
@@ -7,6 +7,7 @@
 #include <fs.h>
 #include <malloc.h>
 #include <os.h>
+#include <sandboxfs.h>
 
 int sandbox_fs_set_blk_dev(struct blk_desc *rbdd, struct disk_partition *info)
 {