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/highbank/highbank.c b/board/highbank/highbank.c
index f7f2e2c..ffde116 100644
--- a/board/highbank/highbank.c
+++ b/board/highbank/highbank.c
@@ -7,6 +7,7 @@
 #include <ahci.h>
 #include <cpu_func.h>
 #include <env.h>
+#include <fdt_support.h>
 #include <net.h>
 #include <netdev.h>
 #include <scsi.h>