net: ethernet: ti: icssg-prueth: Add VLAN support for HSR mode

Add support for VLAN addition/deletion in HSR mode.
In HSR mode, even if the host port is not a member of
the VLAN domain, the slave ports should simply forward the
frames. So allow forwarding of all VLAN frames in HSR mode.

Signed-off-by: Ravi Gunasekaran <r-gunasekaran@ti.com>