Avoid including config.h in command.h

This is not necessary and prevents using this header when building tools.

Signed-off-by: Simon Glass <sjg@chromium.org>

include/command.h

@@ -11,7 +11,6 @@
 #ifndef __COMMAND_H
 #define __COMMAND_H
 
-#include <config.h>
 #include <linker_lists.h>
 
 #ifndef NULL