drm/amd/display: use encoder's engine id to find matched free audio device

drm/amd/display: use encoder's engine id to find matched free audio device

BugLink: https://bugs.launchpad.net/bugs/1840520
[ Upstream commit 74eda776d7a4e69ec7aa1ce30a87636f14220fbb ]

[Why]
On some platforms, the encoder id 3 is not populated. So the encoders
are not stored in right order as index (id: 0, 1, 2, 4, 5) at pool. This
would cause encoders id 4 & id 5 to fail when finding corresponding
audio device, defaulting to the first available audio device. As result,
we cannot stream audio into two DP ports with encoders id 4 & id 5.

[How]
It need to create enough audio device objects (0 - 5) to perform matching.
Then use encoder engine id to find matched audio device.

Signed-off-by: Tai Man <taiman.wong@amd.com>
Reviewed-by: Charlene Liu <Charlene.Liu@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>