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/io.c b/cmd/io.c
index e23ea62..2de1111 100644
--- a/cmd/io.c
+++ b/cmd/io.c
@@ -9,6 +9,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <display_options.h>
 #include <asm/io.h>
 
 /* Display values from last command */