arm: zynq: Add support for Xilinx zc770 xm011 dc2 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, i2c, nand uart, spi and usb.

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