Instead of hoping that our ITR granularity will be 2 usec program the
GLINT_CTL register to make sure the ITR granularity is always 2 usecs.

Now that we know what the ITR granularity will be get rid of the check
in ice_probe() to verify our previous assumption.
Signed-off-by: NBrett Creeley <brett.creeley@intel.com>
Signed-off-by: NAnirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>