common: Drop flash.h from common header

Move this uncommon header out of the common header.

Fix up some style problems in flash.h while we are here.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/freescale/mpc8569mds/mpc8569mds.c b/board/freescale/mpc8569mds/mpc8569mds.c
index cf5d8a5..18e0d87 100644
--- a/board/freescale/mpc8569mds/mpc8569mds.c
+++ b/board/freescale/mpc8569mds/mpc8569mds.c
@@ -7,6 +7,7 @@
 
 #include <common.h>
 #include <console.h>
+#include <flash.h>
 #include <hwconfig.h>
 #include <init.h>
 #include <pci.h>