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/x86/cpu/ivybridge/cpu.c b/arch/x86/cpu/ivybridge/cpu.c
index 8f30cdb..0639b5c 100644
--- a/arch/x86/cpu/ivybridge/cpu.c
+++ b/arch/x86/cpu/ivybridge/cpu.c
@@ -15,6 +15,7 @@
 #include <dm.h>
 #include <errno.h>
 #include <fdtdec.h>
+#include <init.h>
 #include <pch.h>
 #include <asm/cpu.h>
 #include <asm/cpu_common.h>