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/cobra5272/flash.c b/board/cobra5272/flash.c
index e601ed8..5860cd0 100644
--- a/board/cobra5272/flash.c
+++ b/board/cobra5272/flash.c
@@ -7,7 +7,9 @@
 #include <common.h>
 #include <console.h>
 #include <cpu_func.h>
+#include <flash.h>
 #include <irq_func.h>
+#include <uuid.h>
 
 #define PHYS_FLASH_1 CONFIG_SYS_FLASH_BASE
 #define FLASH_BANK_SIZE 0x200000