amd-xgbe: Add support for 10 Mbps speed

Add the necessary changes to support 10 Mbps speed for BaseT and SFP
port modes. This is supported in MAC ver >= 30H.

Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>
Link: https://lore.kernel.org/r/20230109101819.747572-1-Raju.Rangoju@amd.com


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