PATCH] Add support for the Digilent Arty-Z7 Xilinx ZYNQ based board

Patch to add support for the Diligent Arty-Z7 Xilinx ZYNQ based board. This work fine booting FreeBSD 13.1 on my board.

First time submitter, so I appreciate feedback. Regards, Christopher

Signed-off-by: crb@ChrisBowman.com