Merge branch 'net-stmmac-socfpga-1000basex-support-and-cleanups'

Merge branch 'net-stmmac-socfpga-1000basex-support-and-cleanups'

Maxime Chevallier says:

====================
net: stmmac: socfpga: 1000BaseX support and cleanups

This small series sorts-out 1000BaseX support and does a bit of cleanup
for the Lynx conversion.

Patch 1 makes sure that we set the right phy_mode when working in
1000BaseX mode, so that the internal GMII is configured correctly.

Patch 2 removes a check for phy_device upon calling fix_mac_speed(). As
the SGMII adapter may be chained to a Lynx PCS, checking for a
phy_device to be attached to the netdev before enabling the SGMII
adapter doesn't make sense, as we won't have a downstream PHY when using
1000BaseX.

Patch 3 cleans an unused field from the PCS conversion.

v1: https://lore.kernel.org/20250422094701.49798-1-maxime.chevallier@bootlin.com
v2: https://lore.kernel.org/20250423104646.189648-1-maxime.chevallier@bootlin.com
====================

Link: https://patch.msgid.link/20250424071223.221239-1-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>