common: Drop bootstage.h from common header

Move this fairly uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/bosch/shc/board.c b/board/bosch/shc/board.c
index 9698d8e..6e0ad4b 100644
--- a/board/bosch/shc/board.c
+++ b/board/bosch/shc/board.c
@@ -12,6 +12,7 @@
  */
 
 #include <common.h>
+#include <bootstage.h>
 #include <cpu_func.h>
 #include <env.h>
 #include <errno.h>