arm64: zynqmp: Wire mini-emmc0 configuration with zcu100

For testing purpose use zcu100 which has SD at controller 0 and this can
be used for testing this mini configuration.

U-Boot 2018.11-00281-gc5d48466e76e (Nov 30 2018 - 10:41:05 +0100)

Model: ZynqMP MINI EMMC0
Board: Xilinx ZynqMP
DRAM:  512 MiB
EL Level:       EL3
MMC:   sdhci@ff160000: 0
In:    dcc
Out:   dcc
Err:   dcc
ZynqMP>

Signed-off-by: Michal Simek <michal.simek@xilinx.com>