Merge branch 'net: dsa: add support for phylink managed EEE'

Russell King says:

====================
net: dsa: add support for phylink managed EEE

This series adds support for phylink managed EEE to DSA, and converts
mt753x to make use of this feature.

Patch 1 implements a helper to indicate whether the MAC LPI operations
are populated (suggested by Vladimir)

Patch 2 makes the necessary changes to the core code - we retain calling
set_mac_eee(), but this method now becomes a way to merely validate the
arguments when using phylink managed EEE rather than performing any
configuration.

Patch 3 converts the mt7530 driver to use phylink managed EEE.
====================

Link: https://patch.msgid.link/Z6nWujbjxlkzK_3P@shell.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>