net: stmmac: Add glue layer for StarFive JH7110 SoC

This adds StarFive dwmac driver support on the StarFive JH7110 SoC.

Tested-by: Tommaso Merciai <tomm.merciai@gmail.com>
Co-developed-by: Emil Renner Berthing <kernel@esmil.dk>
Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Signed-off-by: Samin Guo <samin.guo@starfivetech.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>