net: dsa: b53: fix toggling vlan_filtering

net: dsa: b53: fix toggling vlan_filtering

To allow runtime switching between vlan aware and vlan non-aware mode,
we need to properly keep track of any bridge VLAN configuration.
Likewise, we need to know when we actually switch between both modes, to
not have to rewrite the full VLAN table every time we update the VLANs.

So keep track of the current vlan_filtering mode, and on changes, apply
the appropriate VLAN configuration.

Fixes: 0ee2af4ebbe3 ("net: dsa: set configure_vlan_while_not_filtering to true by default")
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20250429201710.330937-10-jonas.gorski@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>