When we lock an hwspinlock, we must write the CPU identifier to
the hwspinlock register. If we want to unlock the locked hwspinlock,
we have to rewrite the same CPU identifier.
To define the CPU identifier, we use affinity 1 and affinity 2 fields
of the MPIDR register.
Signed-off-by: Aziz Idomar <aidomar@sequans.com>