ice: Fix forward to queue group logic

When adding a rule, queue region size needs to be provided as log base 2
of the number of queues in region. Fix that.

Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>