Merge branch 'net-dsa-mv88e6xxx-lag-fixes'

Tobias Waldekranz says:

====================
net: dsa: mv88e6xxx: LAG fixes

The kernel test robot kindly pointed out that Global 2 support in
mv88e6xxx is optional.

This also made me realize that we should verify that the hardware
actually supports LAG offloading before trying to configure it.
====================

Link: https://lore.kernel.org/r/20210115125259.22542-1-tobias@waldekranz.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>