PCI: rockchip: Set address alignment for endpoint mode

The address translation unit of the rockchip EP controller does not use
the lower 8 bits of a PCIe-space address to map local memory. Thus we
must set the align feature field to 256 to let the user know about this
constraint.

Link: https://lore.kernel.org/r/20230418074700.1083505-12-rick.wertenbroek@gmail.com
Fixes: cf590b0 ("PCI: rockchip: Add EP driver for Rockchip PCIe controller")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Rick Wertenbroek <rick.wertenbroek@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: stable@vger.kernel.org

Author: damien-lemoal

drivers/pci/controller/pcie-rockchip-ep.c

@@ -442,6 +442,7 @@ static const struct pci_epc_features rockchip_pcie_epc_features = {
 	.linkup_notifier = false,
 	.msi_capable = true,
 	.msix_capable = false,
+	.align = 256,
 };
 
 static const struct pci_epc_features*