drm/panthor: Use common pattern for interrupt handlers everywhere.

We want to allow for platforms where all GPU interrupts are shared and we don't want to keep the hard interrupt handler running for too long, so we need to switch to threaded interrupt handlers everywhere in the panthor code. Use a common pattern of a small hard interrupt handler that only checks that the interrupt was generated by the relevant block and if so it masks future interrupts from the same source before waking up the threaded handler. The threaded handler does the main work before unmasking the interrupt sources at the end.

Signed-off-by: Liviu Dudau liviu.dudau@arm.com