net/cxgbe: support flow API for matching all packets on PF

net/cxgbe: support flow API for matching all packets on PF

Add support to match all packets received on the underlying PF

Note that the same 17-bit hardware tuple is shared between QinQ
and PF match. Hence, match on either QinQ or PF only can be done
at a time. Both QinQ and PF match can't be enabled at the same time.

Also, remove check to reject rules without spec because
RTE_FLOW_ITEM_TYPE_PF doesn't require a spec. Due to this check
removal, RTE_FLOW_ITEM_TYPE_PHY_PORT item needs to be updated to
handle NULL spec

Signed-off-by: Karra Satwik <kaara.satwik@chelsio.com>
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>