net: phy: microchip_t1: SQI support for LAN887x

Add support for measuring Signal Quality Index for LAN887x T1 PHY.
Signal Quality Index (SQI) is measure of Link Channel Quality from
0 to 7, with 7 as the best. By default, a link loss event shall
indicate an SQI of 0.

Signed-off-by: Tarun Alle <Tarun.Alle@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20241007063943.3233-1-tarun.alle@microchip.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>