common: Drop init.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/tplink/wdr4300/wdr4300.c b/board/tplink/wdr4300/wdr4300.c
index 4dacaa4..7e73395 100644
--- a/board/tplink/wdr4300/wdr4300.c
+++ b/board/tplink/wdr4300/wdr4300.c
@@ -4,6 +4,7 @@
  */
 
 #include <common.h>
+#include <init.h>
 #include <asm/io.h>
 #include <asm/addrspace.h>
 #include <asm/types.h>