nitrogen6x: config: enable "i2c edid"

Enable the "i2c edid" command to query data from an attached
HDMI monitor.

Usage is typically this:

        U-Boot > i2c dev 1
        U-Boot > i2c edid 0x50
        ...

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
diff --git a/include/configs/nitrogen6x.h b/include/configs/nitrogen6x.h
index 82dc0fc..b911d06 100644
--- a/include/configs/nitrogen6x.h
+++ b/include/configs/nitrogen6x.h
@@ -63,6 +63,7 @@
 #define CONFIG_SYS_I2C
 #define CONFIG_SYS_I2C_MXC
 #define CONFIG_SYS_I2C_SPEED		100000
+#define CONFIG_I2C_EDID
 
 /* MMC Configs */
 #define CONFIG_FSL_ESDHC