drivers: introduce hardware spinlock framework

The intention of hardware spinlock is to allow two processors,
that have no alternative mechanism for accomplish synchronization
and mutual exclusion operations, to share resources (such as
memory and/or any other element).

Here, we add the hwspinlock framework, that makes possible to use
those hwspinlock devices and stay platform-independent. Each
platform wishing to support hardware spinlock must describe a
driver using this framework.

Signed-off-by: Aziz Idomar <aidomar@sequans.com>