common: Drop image.h from common header

Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/sunxi/board.c b/board/sunxi/board.c
index 6afea6e..e210824 100644
--- a/board/sunxi/board.c
+++ b/board/sunxi/board.c
@@ -14,6 +14,7 @@
 #include <dm.h>
 #include <env.h>
 #include <hang.h>
+#include <image.h>
 #include <init.h>
 #include <mmc.h>
 #include <axp_pmic.h>