Introduce cpumask_nth_and_andnot() based on find_nth_and_andnot_bit().
It's used in the following patch to traverse cpumasks without storing
intermediate result in temporary cpumask.
Signed-off-by: Yury Norov <yury.norov@gmail.com> Acked-by: Tariq Toukan <tariqt@nvidia.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Peter Lafreniere <peter@n8pjl.ca> Signed-off-by: Jakub Kicinski <kuba@kernel.org>