patches/openwrt: fix Turris 1.x kernel not booting and missing DSA

This fixes previous configuration rework. For some reason we lost DSA (possibly in some rebase) and also devicetree was invalid. Compatible field is primarily used to match drivers so changing it is no way possible.

Fixes https://gitlab.labs.nic.cz/turris/turris-build/issues/124 and https://gitlab.labs.nic.cz/turris/turris-build/issues/125