reset: reset-zynqmp: Adding support for Xilinx zynqmp reset controller.

Add a reset controller driver for Xilinx Zynq UltraScale+ MPSoC.
The zynqmp reset-controller has the ability to reset lines
connected to different blocks and peripheral in the Soc.

Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>