if you need these drivers, you cannot use 4.19…normally x.xx-main is the right one for r2…for 5.2 i have not upgraded to final and merged the feature-branches. also second gmac is not ported because we try to realize this with phylink (in 5.2 net-next-patches are needed).
as a first start you can use 5.2-rc (if you do not need poweroff, hdmi and internal wifi). else you have to merge by yourself or wait till i have done it…
currently busy because of phylink/mainline-network on r64
basicly openwrt uses same kernel, but by default it is built inside the image and cannot replaced so easy. see the openwrt-repo from lexa2 how to get an openwrt with partitions…with this image you can replace kernel on boot-partition, but if you use my kernels you maybe have to swap mmc back (openwrt using mainline-kernel which does not swap mmc i’ve done for debian/ubuntu). simply revert the mmc-swap-commit
edit: have now created 5.2-main and merged poweroff+ wifi