This commit adds support for Xilinx ZynqMP boards to the OPTEE/build repository.
The provided makefile relies on Xilinx Petalinux 2018.2 itself based on Yocto.
The makefile helps to create, patch and build a customized Petalinux project
with OPTEE support. Boards can be emulated using Petalinux's QEMU.

Signed-off-by: Michael Grand <michael.grand.mg@gmail.com>
Acked-by: Etienne Carriere <etienne.carriere@linaro.org>
Tested-by: Michael Grand <michael.grand.mg@gmail.com>