Merge branch 'net-pcs-add-supported_interfaces-bitmap-for-pcs'

Russell King says:

====================
net: pcs: add supported_interfaces bitmap for PCS

This series adds supported_interfaces for PCS, which gives MAC code
a way to determine the interface modes that the PCS supports without
having to implement functions such as xpcs_get_interfaces(), or
workarounds such as in

 https://lore.kernel.org/20241213090526.71516-3-maxime.chevallier@bootlin.com

Patch 1 adds the new bitmask to struct phylink_pcs, and code within
phylink to validate that the PCS returned by the MAC driver supports
the interface mode - but only if this bitmask is non-empty.

Patch 2 through 4 fills in the interface modes for XPCS, Mediatek LynxI
and Lynx PCS.

Patch 5 adds support to stmmac to make use of this bitmask when filling
in phylink_config.supported_interfaces, eliminating the call to
xpcs_get_interfaces.

As xpcs_get_interfaces() is now unused outside of pcs-xpcs.c, patch 6
makes this function static and removes it from the header file.
====================

Link: https://patch.msgid.link/Z3fG9oTY9F9fCYHv@shell.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>