ice: Set default value for ITR in alloc function

When the user sets itr_setting to zero from ethtool -C, the driver changes
this value to default in ice_cfg_itr (for example after changing ring
param). Remove code that sets default value in ice_cfg_itr and move it to
place where the driver allocates q_vectors.

Signed-off-by: Michal Swiatkowski <michal.swiatkowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>