drm/amd/display: Notify DMCUB of D0/D3 state

drm/amd/display: Notify DMCUB of D0/D3 state

[Why]
We want to avoid arming the HPD timer in firmware when preparing for
S0i3 entry when DC is considered in D3.

[How]
Notify DMCUB of the power state transitions so it can decide to arm
the HPD timer for idle in DCN35 only in D0.

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Ovidiu Bunea <Ovidiu.Bunea@amd.com>
Signed-off-by: Zaeem Mohamed <zaeem.mohamed@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>