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/arm/mach-sunxi/dram_sun6i.c b/arch/arm/mach-sunxi/dram_sun6i.c
index f473230..8e78126 100644
--- a/arch/arm/mach-sunxi/dram_sun6i.c
+++ b/arch/arm/mach-sunxi/dram_sun6i.c
@@ -11,6 +11,7 @@
  */
 #include <common.h>
 #include <errno.h>
+#include <init.h>
 #include <asm/io.h>
 #include <asm/arch/clock.h>
 #include <asm/arch/dram.h>