i40iw: Set TOS field in IP header

Set the TOS field in IP header with the value passed in
from application. If there is mismatch between the remote
client's TOS and listener, set the listener Tos to the higher
of the two values.

Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Faisal Latif <faisal.latif@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>