net/i40e: fix input set field mask

net/i40e: fix input set field mask

The absolute field offsets of IPv4 or IPv6 header are related to
hardware configuration. The X710 and X722 have different hardware
configurations, and users can even modify the hardware configuration.
Therefore, The default values cannot be used when calculating mask
offset.

The following flows can be created on X722 NIC, but the packet will
not enter the queue 3:
  flow create 0 ingress pattern eth / ipv4 proto is 255  / end
  actions queue index 3 / end
  pkt = Ether()/IP(ttl=63, proto=255)/Raw('X'*40)

  flow create 0 ingress pattern eth / ipv4 tos is 50 / udp / end
  actions queue index 3 / end
  pkt = Ether()/IP(tos=50)/UDP()/Raw('X'*40)

  flow create 0 ingress pattern eth / ipv6 tc is 12 / udp / end
  actions queue index 3 / end
  pkt = Ether()/IPv6(tc=12,hlim=34,fl=0x98765)/UDP()/Raw('X'*40)

  flow create 0 ingress pattern eth / ipv6 hop is 34 / end actions
  queue index 3 / end
  pkt = Ether()/IPv6(tc=12,hlim=34,fl=0x98765)/Raw('X'*40)

This patch read the field offsets from the NIC and return the mask
register value.

Fixes: 98f055707685 ("i40e: configure input fields for RSS or flow director")
Fixes: 92cf7f8ec082 ("i40e: allow filtering on more IP header fields")
Cc: stable@dpdk.org
Signed-off-by: Alvin Zhang <alvinx.zhang@intel.com>
Tested-by: Lingli Chen <linglix.chen@intel.com>