PCI: dwc: endpoint: Implement the pci_epc_ops::align_addr() operation

The function dw_pcie_prog_outbound_atu() used to program outbound ATU
entries for mapping RC PCI addresses to local CPU addresses does not
allow PCI addresses that are not aligned to the value of region_align
of struct dw_pcie. This value is determined from the iATU hardware
registers during probing of the iATU (done by dw_pcie_iatu_detect()).
This value is thus valid for all DWC PCIe controllers, and valid
regardless of the hardware configuration used when synthesizing the
DWC PCIe controller.

Implement the ->align_addr() endpoint controller operation to allow
this mapping alignment to be transparently handled by endpoint function
drivers through the function pci_epc_mem_map().

Link: https://lore.kernel.org/linux-pci/20241012113246.95634-7-dlemoal@kernel.org
Link: https://lore.kernel.org/linux-pci/20241015090712.112674-1-dlemoal@kernel.org
Link: https://lore.kernel.org/linux-pci/20241017132052.4014605-5-cassel@kernel.org


Co-developed-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
[mani: squashed the patch that changed phy_addr_t to u64]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[kwilczynski: squashed patch that updated the pci_size variable]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>