dt-bindings: PHY: P2U: Add support for Tegra234 P2U block

Add support for Tegra234 P2U (PIPE to UPHY) module block which is a glue
module instantiated once for each PCIe lane between Synopsys DesignWare
core based PCIe IP and Universal PHY block.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220629060435.25297-2-vidyas@nvidia.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>