alarm: remove direct access to interrupt handle

alarm: remove direct access to interrupt handle

Removing direct access to interrupt handle structure fields,
rather use respective get set APIs for the same.
Making changes to all the libraries access the interrupt handle fields.

Implementing alarm cleanup routine, where the memory allocated
for interrupt instance can be freed.

Signed-off-by: Harman Kalra <hkalra@marvell.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
Tested-by: Raslan Darawsheh <rasland@nvidia.com>