drm/amd/display/dc: add helper for panic updates

Add a DC helper for panic updates.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Lu Yao <yaolu@kylinos.cn>
Cc: Jocelyn Falempe <jfalempe@redhat.com>
Cc: Harry Wentland <harry.wentland@amd.com>