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/variscite/dart_6ul/spl.c b/board/variscite/dart_6ul/spl.c
index 798523d..1b06a66 100644
--- a/board/variscite/dart_6ul/spl.c
+++ b/board/variscite/dart_6ul/spl.c
@@ -5,6 +5,7 @@
  */
 
 #include <common.h>
+#include <init.h>
 #include <spl.h>
 #include <asm/arch/clock.h>
 #include <asm/io.h>