Merge branch 'net-stmmac-Add-ethtool-support-for-get-set-channels'

Wong Vee Khee says:

====================
net: stmmac: Add ethtool support for get|set channels

This patch set is to add support for user to get or set Tx/Rx channel
via ethtool. There are two patches that fixes bug introduced on upstream
in order to have the feature work.

Tested on Intel Tigerlake Platform.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>