ramips: 5.10: port and refresh patches, ralink drv

ramips: 5.10: port and refresh patches, ralink drv

Enable testing kernel.

Fix compile errors by using new kernel APIs.

Fix fuzz by manually editing patches to ensure the code goes in the
right place.

For 721-NET-no-auto-carrier-off-support.patch, revert upstream commit
a307593a6 to keep the OpenWrt ralink driver operational.

Add mt7621-pci-phy patch to select REGMAP_MMIO as discussed in PR #3693
and #3952.

Run automatic quilt refresh on the rest.

Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>