phy: tegra: Add PCIe PIPE2UPHY support for Tegra234

Synopsys DesignWare core based PCIe controllers in Tegra234 SoC
interface with Universal PHY (UPHY) module through a PIPE2UPHY (P2U)
module. For each PCIe lane of a controller, there is a P2U unit
instantiated at hardware level. This driver provides support for the
programming required for each P2U that is going to be used for a PCIe
controller.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Link: https://lore.kernel.org/r/20220629060435.25297-9-vidyas@nvidia.com


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