Drop config.h header from display_options.c

Since common.h will always include this automatically, it is not needed.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/display_options.c b/lib/display_options.c
index 4f2961f..29343fc 100644
--- a/lib/display_options.c
+++ b/lib/display_options.c
@@ -5,7 +5,6 @@
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
-#include <config.h>
 #include <common.h>
 #include <console.h>
 #include <div64.h>