mcx: Enable command line editing

Signed-off-by: Detlev Zundel <dzu@denx.de>
CC: Stefano Babic <sbabic@denx.de>
diff --git a/include/configs/mcx.h b/include/configs/mcx.h
index f3d26ea..1315c3c 100644
--- a/include/configs/mcx.h
+++ b/include/configs/mcx.h
@@ -219,6 +219,8 @@
 	"else run nandboot; fi"
 
 #define CONFIG_AUTO_COMPLETE
+#define CONFIG_CMDLINE_EDITING
+
 /*
  * Miscellaneous configurable options
  */