net: stmmac: add EHL RGMII 1Gbps PCI info and PCI ID

Added EHL RGMII 1Gbps PCI ID. Different MII and speed will have
different PCI ID.

Signed-off-by: Voon Weifeng <weifeng.voon@intel.com>
Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>