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/qualcomm/dragonboard820c/dragonboard820c.c b/board/qualcomm/dragonboard820c/dragonboard820c.c
index 3134415..c1ade5c 100644
--- a/board/qualcomm/dragonboard820c/dragonboard820c.c
+++ b/board/qualcomm/dragonboard820c/dragonboard820c.c
@@ -6,6 +6,7 @@
  */
 
 #include <cpu_func.h>
+#include <init.h>
 #include <asm/arch/sysmap-apq8096.h>
 #include <env.h>
 #include <asm/cache.h>