drm/amd/display: Fix DP no audio issue

drm/amd/display: Fix DP no audio issue

[ Upstream commit 3886b198bd6e49c801fe9552fcfbfc387a49fbbc ]

[why]
need to enable APG_CLOCK_ENABLE enable first
also need to wake up az from D3 before access az block

Reviewed-by: Swapnil Patel <swapnil.patel@amd.com>
Signed-off-by: Charlene Liu <Charlene.Liu@amd.com>
Signed-off-by: Chenyu Chen <chen-yu.chen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit bf5e396957acafd46003318965500914d5f4edfa)
Signed-off-by: Sasha Levin <sashal@kernel.org>