net: phy: nxp-c45-tja11xx: reset PCS if the link goes down

commit b69691c51b7b83f53f383abd024b7d3dfc4a3c82 from
https://github.com/nxp-auto-linux/linux



During PTP testing on early TJA1120 engineering samples I observed that
if the link is lost and recovered, the tx timestamps will be randomly
lost. To avoid this HW issue, the PCS should be reset.

Resetting the PCS will break the link and we should reset the PCS on
LINK UP -> LINK DOWN transition, otherwise we will trigger and infinite
loop of LINK UP -> LINK DOWN events.

Issue: ALB-10440

Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20230731091619.77961-12-radu-nicolae.pirea@oss.nxp.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
(cherry picked from commit 68c6af72)
Signed-off-by: Zhantao Tang <zhantao.tang@windriver.com>