PCI: imx6: Fix i.MX8MP PCIe EP's occasional failure to trigger MSI

Correct occasional MSI triggering failures in i.MX8MP PCIe EP by applying
the correct hardware outbound alignment requirement.

The i.MX platform has a restriction about outbound address translation. The
pci-epc-mem uses page_size to manage it. Set the correct page_size for i.MX
platform to meet the hardware requirement, which is the same as inbound
address alignment.

Thus, align it with epc_features::align.

Fixes: 1bd0d43 ("PCI: imx6: Clean up addr_space retrieval code")
Link: https://lore.kernel.org/linux-pci/20240729-pci2_upstream-v8-2-b68ee5ef2b4d@nxp.com
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Jason Liu <jason.hui.liu@nxp.com>
Cc: <stable@vger.kernel.org> # 6.9+

Author: Richard Zhu

drivers/pci/controller/dwc/pci-imx6.c

@@ -1113,6 +1113,8 @@ static int imx6_add_pcie_ep(struct imx6_pcie *imx6_pcie,
 	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_SUPPORT_64BIT))
 		dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
 
+	ep->page_size = imx6_pcie->drvdata->epc_features->align;
+
 	ret = dw_pcie_ep_init(ep);
 	if (ret) {
 		dev_err(dev, "failed to initialize endpoint\n");