This adds support for configuring the PRG_ETHERNET_ADDR registers on Meson 8b (S805) and GXBB (S905) devices. The registers there are completely different from those found in the earlier Meson 6b SoC series, which is why a new driver was implemented.
This configuration is required when the bootloader does not configure these registers based on the connected PHY. Symptoms are that the DWMAC device is detected, but no packets are getting through, even though everything else is configured correctly.
