gflt200: enabled support for the diag command.

The diag command supports running POST tests from the command line.

Change-Id: Ie225ec70311eb82ced86e6b3a3f3886487047901
diff --git a/include/configs/gflt200.h b/include/configs/gflt200.h
index 7490d56..164aed4 100644
--- a/include/configs/gflt200.h
+++ b/include/configs/gflt200.h
@@ -4,6 +4,8 @@
 
 #undef MV_INCLUDE_RTC
 
+#define CONFIG_CMD_DIAG
+
 #define CONFIG_RTC_PCF8523
 #define CONFIG_SYS_I2C_RTC_ADDR	0x68