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/drivers/timer/timer-uclass.c b/drivers/timer/timer-uclass.c
index b619200..14dde95 100644
--- a/drivers/timer/timer-uclass.c
+++ b/drivers/timer/timer-uclass.c
@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <dm.h>
+#include <init.h>
 #include <dm/lists.h>
 #include <dm/device-internal.h>
 #include <dm/root.h>