Add PSGTR driver for Xilinx ZynqMP.
The most of configurations are taken from Linux kernel psgtr driver.
USB3.0 and SGMII configurations are tested on SOM. In SGMII case also
IOU_SLCR reg is updated to get proper clock setup and signal detection
configuration.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Link: https://lore.kernel.org/r/36e6e9d3baf8511af1916e91e4887032ca2b6c20.1641458978.git.michal.simek@xilinx.com
