imx: 6.6: add a patch to work around a PCI init hang on IMX8M{M,P}

imx: 6.6: add a patch to work around a PCI init hang on IMX8M{M,P}

The act of attempting link at gen1 then trying to link at higher speeds
causes a hang with the specific PCIe switch used on the Gateworks Venice
boards. Work around this by linking at the highest speed first as is
common with all other PCI controller drivers.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Link: https://github.com/openwrt/openwrt/pull/17717
Signed-off-by: Robert Marko <robimarko@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/17762
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
(cherry picked from commit 23a18a57cf750d9081353cdd34e44982ea10e191)