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/freescale/t208xrdb/eth_t208xrdb.c b/board/freescale/t208xrdb/eth_t208xrdb.c
index 669bc1e..db47181 100644
--- a/board/freescale/t208xrdb/eth_t208xrdb.c
+++ b/board/freescale/t208xrdb/eth_t208xrdb.c
@@ -7,6 +7,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <fdt_support.h>
 #include <net.h>
 #include <netdev.h>
 #include <asm/mmu.h>