drivers: firmware: nrf_ironside: add IRONside update service

Add an IPC service API for triggering updates of the Nordic IRONside SE
firmware using the IRONside call module.

Co-authored-by: Håkon Amundsen <haakon.amundsen@nordicsemi.no>
Signed-off-by: Jonathan Nilsen <jonathan.nilsen@nordicsemi.no>