net: phy: don't try to setup PHY-driven SFP cages when using genphy

net: phy: don't try to setup PHY-driven SFP cages when using genphy

We don't have support for PHY-driver SFP cages with the genphy code.

On top of that, it was found by sashiko that running
sfp_bus_add_upstream() for genphy deadlocks, as for genphy the PHY
probing runs under RTNL, which isn't the case for non-genphy drivers.

This problem was reproduced, and does lead to a deadlock on RTNL.

Before the blamed commit, the phy_sfp_probe() call was made by
individual PHY drivers, so there was no way to get to the SFP probing
path when using genphy.

Let's therefore only run phy_sfp_probe when not using genphy.

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Fixes: bad869b5e41a ("net: phy: Only rely on phy_port for PHY-driven SFP")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260604092819.723505-5-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>