board: engicam: Remove bogus check for mmc for imx6ul isiot

imx6ul-isiot-mmc.dts was removed in uboot version v2018.03 and from then
onwards IMX6UL isiot uses imx6ul-isiot-emmc.dts for mmc, so remove
unnecessary check for mmc.

Signed-off-by: Shyam Saini <shyam.saini@amarulasolutions.com>
1 file changed