Add phys properties so Linux can power-on/configure the GTR transceivers
(xlnx,zynqmp-psgtr-v1.1).

Link: https://lore.kernel.org/r/20240531161337.864994-2-sean.anderson@linux.devSigned-off-by: Sean Anderson <sean.anderson@linux.dev>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>