drm/amd/display: fix audio endpoint not getting disabled issue

[Why]
Disable_audio_stream gets enum option as a paramenter which will decide
if we free acquired resources or not. However checks for the option is
guarded by the other condition which check if audio stream is getting
diabled more than once. With both conditions combined, if we attempt to
disable audio stream twice in a row, first with keep and second with
free as an option, we will never free any resources, which will make
system think there is audio endpoint connected even after we plug out
the device

[How]
Get rid of option as parameter to disable_audio_stream and move the part
of the code that free acquired resources to outside where to keep or to
free resources is actually determined

Signed-off-by: Su Sung Chung <Su.Chung@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>