net/cxgbe: ignore flow default masks for unrequested fields

net/cxgbe: ignore flow default masks for unrequested fields

commit 536db938a444 ("net/cxgbe: add devargs to control filtermode and
filtermask") allows configuring hardware to select specific combination
of header fields to match in the incoming packets. However, the default
mask is set for all fields in the requested pattern items, even if the
field is not explicitly set in the combination and results in
validation errors. To prevent this, ignore setting the default masks
for the unrequested fields and the hardware will also ignore them in
validation, accordingly. Also, tweak the filter spec before finalizing
the masks.

Fixes: 536db938a444 ("net/cxgbe: add devargs to control filtermode and filtermask")
Cc: stable@dpdk.org
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>