PCI: xilinx-cpm: Add support for Versal Net CPM5NC Root Port controller

The Versal Net ACAP (Adaptive Compute Acceleration Platform) devices
incorporate the Coherency and PCIe Gen5 Module, specifically the
Next-Generation Compact Module (CPM5NC).

The integrated CPM5NC block, along with the built-in bridge, can function
as a PCIe Root Port and supports the PCIe Gen5 protocol with data transfer
rates of up to 32 GT/s, and is capable of supporting up to a x16 lane-width
configuration.

Bridge errors are managed using a specific interrupt line designed for
CPM5N. The INTx interrupt support is not available.

Currently in this commit platform specific bridge errors support is not
added.

Signed-off-by: Thippeswamy Havalige <thippeswamy.havalige@amd.com>
[kwilczynski: commit log, squashed patch to fix an if-statement condition
to ensure that xilinx_cpm_pcie_init_port() does not run on the CPM5NC_HOST
variant from https://lore.kernel.org/linux-pci/20250311072402.1049990-1-thippeswamy.havalige@amd.com

]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20250224155025.782179-4-thippeswamy.havalige@amd.com