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/arch/arc/lib/cpu.c b/arch/arc/lib/cpu.c
index 8324655..f032f3e 100644
--- a/arch/arc/lib/cpu.c
+++ b/arch/arc/lib/cpu.c
@@ -4,6 +4,7 @@
  */
 
 #include <common.h>
+#include <init.h>
 #include <malloc.h>
 #include <vsprintf.h>
 #include <asm/arcregs.h>