Bridge address base is common PLDA field, add this to struct mc_pcie first.

INTx and MSI interrupt code will be changed to common code, so get the
bridge base address from port->bridge_addr instead of axi_base_addr.
The axi_base_addr is Microchip-specific data.

Link: https://lore.kernel.org/linux-pci/20240328091835.14797-5-minda.chen@starfivetech.comSigned-off-by: Minda Chen <minda.chen@starfivetech.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>