net: ethernet: l2: Add support for VLAN tag strip

If ethernet controller has VLAN tag strip flag enabled
(ETHERNET_HW_VLAN_TAG_STRIP), L2 etherent will not read tag from
the Rx etherent header. Instead it will fetch VLAN tag from
net packet metadata.

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