ice: add support for DSCP QoS for IDC

The ice driver provides QoS information to auxiliary drivers
through the exported function ice_get_qos_params.  This function
doesn't currently support L3 DSCP QoS.

Add the necessary defines, structure elements and code to support
DSCP QoS through the IIDC functions.

Signed-off-by: Dave Ertman <david.m.ertman@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>