Use linux-firmware repository for IPQ5018, IPQ8074 and QCN9074.
All officially released firmware versions are available there.
Signed-off-by: Paweł Owoc <frut3k7@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/21833
Signed-off-by: Robert Marko <robimarko@gmail.com>