net: airoha: Add missing stats to ethtool_eth_mac_stats

Add the following stats to ethtool ethtool_eth_mac_stats stats:
- FramesTransmittedOK
- OctetsTransmittedOK
- FramesReceivedOK
- OctetsReceivedOK

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20251013-airoha-ethtool-improvements-v1-1-fdd1c6fc9be1@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>