net: phy: drop phy_settings and the associated lookup helpers

The phy_settings array is no longer relevant as it has now been replaced
by the link_caps array and associated phy_caps helpers.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20250307173611.129125-11-maxime.chevallier@bootlin.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>