net: txgbe: change LAN reset mode

The old way to do LAN reset is sending reset command to firmware. Once
firmware performs reset, it reconfigures what it needs.

In the new firmware versions, veto bit is introduced for NCSI/LLDP to
block PHY domain in LAN reset. At this point, writing register of LAN
reset directly makes the same effect as the old way. And it does not
reset MNG domain, so that veto bit does not change.

Since veto bit was never used, the old firmware is compatible with the
driver before and after this change. The new firmware needs to use with
the driver after this change if it wants to implement the new feature,
otherwise it is the same as the old firmware.

Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20230717021333.94181-1-jiawenwu@trustnetic.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>