common: Drop display_options.h from common header

Move this out of the common header and include it only where needed.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/cmd/mem.c b/cmd/mem.c
index 1f4e3fc..6a7b401 100644
--- a/cmd/mem.c
+++ b/cmd/mem.c
@@ -16,6 +16,7 @@
 #include <cli.h>
 #include <command.h>
 #include <console.h>
+#include <display_options.h>
 #ifdef CONFIG_MTD_NOR_FLASH
 #include <flash.h>
 #endif