drm/amd/display: Register VUPDATE_NO_LOCK interrupts for DCN2

[Why]
These are needed to send back DRM vblank events in the case where VRR
is on. Without the interrupt enabled we're deferring the events into the
vblank queue and userspace is left waiting forever to get back the
events they need.

Found using igt@kms_vrr - the test fails immediately due to vblank
timeout.

[How]
Register them the same way we're handling it for DCN1.

This fixes igt@kms_vrr for DCN2.

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: David Francis <David.Francis@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>