Rebuilding CP VSI each time the PR is created drastically increase the
time of maximum VFs creation. Add function to reserve number of CP
queues to deal with this problem.

Use the same function to decrease number of queues in case of removing
VFs. Assume that caller of ice_eswitch_reserve_cp_queues() will also
call ice_eswitch_attach/detach() correct number of times.

Still one by one PR adding is handy for VF resetting routine.
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Tested-by: Sujai Buvaneswaran <sujai.buvaneswaran@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>