net: airoha: Enable TSO/Scatter Gather for LAN port

Set net_device vlan_features in order to enable TSO and Scatter Gather
for DSA user ports.

Reviewed-by: Mateusz Polchlopek <mateusz.polchlopek@intel.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250304-lan-enable-tso-v1-1-b398eb9976ba@kernel.org


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