net: ethernet: stmmac: add missing sgmii configure for ipq806x

The different gmacid require different configuration based on the soc
and on the gmac id. Add these missing configuration taken from the
original driver.

Signed-off-by: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com>
Link: https://lore.kernel.org/r/20220614112228.1998-1-ansuelsmth@gmail.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>