Merge branch 'qcom-phy-possible'

Robert Marko says:

====================
net: phy: qcom: qca808x: fill in possible_interfaces

QCA808x does not currently fill in the possible_interfaces.

This leads to Phylink not being aware that it supports 2500Base-X as well
so in cases where it is connected to a DSA switch like MV88E6393 it will
limit that port to phy-mode set in the DTS.

That means that if SGMII is used you are limited to 1G only while if
2500Base-X was set you are limited to 2.5G only.

Populating the possible_interfaces fixes this.

Changes in v2:
* Get rid of the if/else by Russels suggestion in the helper
====================

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