drm/amd/display: Update dchubbub.h for hubbub perfmon support

[why]
dchubbub supports performance monitoring for hubbub.
The interfaces define the performance monitoring events and their
attributes.

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>