igb: add xdp frags support to ndo_xdp_xmit

Add the capability to map non-linear xdp frames in XDP_TX and
ndo_xdp_xmit callback.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Tested-by: Chandan Kumar Rout <chandanx.rout@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20220711230751.3124415-1-anthony.l.nguyen@intel.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>