i40e/i40evf: Add TX/RX outer UDP checksum support for X722

X722 supports offloading of outer UDP TX and RX checksum for tunneled
packets. This patch exposes the support and leaves it enabled by
default.

Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Jim Young <james.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>