drm/i915/psr: Add interface to notify PSR of vblank enable/disable

To implement Wa_16025596647 we need to get notification of vblank interrupt
enable/disable. Add new interface to PSR code for this notification.

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: https://lore.kernel.org/r/20250414100508.1208774-10-jouni.hogander@intel.com