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/Marvell/db-88f6820-amc/db-88f6820-amc.c b/board/Marvell/db-88f6820-amc/db-88f6820-amc.c
index 372beb3..f225f46 100644
--- a/board/Marvell/db-88f6820-amc/db-88f6820-amc.c
+++ b/board/Marvell/db-88f6820-amc/db-88f6820-amc.c
@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <i2c.h>
+#include <init.h>
 #include <miiphy.h>
 #include <net.h>
 #include <netdev.h>