drm/amd/display: Add available bandwidth calculation for audio

drm/amd/display: Add available bandwidth calculation for audio

[Why]
Audio for 8K 240Hz monitor was not available when it should be

[How]
Added calculation based on stream state

Co-developed-by: Ryan Seto <ryanseto@amd.com>
Reviewed-by: George Shen <george.shen@amd.com>
Signed-off-by: Jerry Zuo <jerry.zuo@amd.com>
Signed-off-by: Ryan Seto <ryanseto@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>