ice: get rid of num_lan_msix field

Remove the field to allow having more queues than MSI-X on VSI. As
default the number will be the same, but if there won't be more MSI-X
available VSI can run with at least one MSI-X.

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@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>