Merge branch 'net-dsa-microchip-implement-phy-loopback'

Oleksij Rempel says:

====================
net: dsa: microchip: implement PHY loopback
====================

Link: https://lore.kernel.org/r/20240124123314.734815-1-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>