PCI: rockchip: Set address alignment for endpoint mode

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: cf590b078391 ("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