[qca-nss-sfe] Support VLAN offload in SFE in tunipip6

VLAN tagging(encapsulation) and untag(decapsulation)
can be accelerated in SFE for tunipip6.

Signed-off-by: Tian Yang <quic_tiany@quicinc.com>
Change-Id: I2723cbe426fc85a8292c12be5abb8b1ca663772f
3 files changed