net: ethernet: Add VLAN tag stripping capability flag

Some ethenet controllers want to strip the VLAN tag from
ethernet Rx frames and feed the packet into proper interface
queue based on the tag. Add this flag to get_capabilities()
to provide VLAN tag stripping feature to the controller.

Signed-off-by: Ravi kumar Veeramally <ravikumar.veeramally@linux.intel.com>