ice: handle DCBx non-contiguous TC request

If DCBx request non-contiguous TCs, then the driver will configure default
traffic class (TC0). This is done to prevent Tx hang since the driver
currently does not support non-contiguous TC.

Signed-off-by: Paul Greenwalt <paul.greenwalt@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>