ice: reword comments referring to control queues

Many comments in ice_controlq.c use the term "Admin queue" despite the code
being intended for arbitrary control queues, not just the Admin queue.
Reword the comments to make it clear that this code is the generic control
queue logic that is shared by all of the control queues, and is not
specific to the Admin queue.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>