IB/hfi1: Create common functions for affinity CPU mask operations

CPU masks are used to keep track of affinity assignments for IRQs
and processes. Operations performed on these affinity CPU masks are
duplicated throughout the code.

Create common functions for affinity CPU mask operations to remove
duplicate code.

Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>