arm: zynq: Add support for Xilinx zc770 xm012 dc3 board

zc770 is based board which is extended by FMC/DC cards for SoC
validation. FMCs/DCs are supposed to cover all SoC configurations.
FMC/DC contains can, 2x i2c, nor flash, spi and uart.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Rob Herring <robh@kernel.org>