ice: count combined queues using Rx/Tx count

Previous implementation assumes that there is 1:1 matching between
vectors and queues. It isn't always true.

Get minimum value from Rx/Tx queues to determine combined queues number.

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com>
Signed-off-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>