u-boot-odroidxu3: check if eMMC is present
u-boot-odroidxu3: check if eMMC is present

Modify the U-Boot boot script to check if eMMC device is present on
board. Based on result of that check find the proper SD card device
(/dev/mmcblkX). Without this patch BSP would not boot from SD card
on boards without eMMC connected.

Signed-off-by: Guillaume Tucker <e7e20b7c30f19d4ca6b81319ef81bf200369d137@arm.com>

ARM-software/meta-mali,nezticle/meta-mali,nezticle/meta-mali,ARM-software/meta-mali,nezticle/meta-mali,ARM-software/meta-mali