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/renesas/silk/silk.c b/board/renesas/silk/silk.c
index e7cbd75..db88f0d 100644
--- a/board/renesas/silk/silk.c
+++ b/board/renesas/silk/silk.c
@@ -10,6 +10,7 @@
 #include <cpu_func.h>
 #include <env.h>
 #include <hang.h>
+#include <init.h>
 #include <malloc.h>
 #include <dm.h>
 #include <dm/platform_data/serial_sh.h>