Backport patch
8b6836d82470 ("net: dsa: mv88e6xxx: keep the pvid at 0 when VLAN-unaware")
from 5.15.
Keeping the pvid at 0 when VLAN-unaware makes it possible to drop the
hack introduced in commit 920eaab1d8 ("kernel: DSA roaming fix for
Marvell mv88e6xxx"). Dropping the hack makes it possible to use VLAN
interfaces with VID 1 on DSA ports without problems with FDB.
Signed-off-by: Marek Behún <kabel@kernel.org>
