hal: voice_extn: update error handling for incall music usecase

Update error handling for incall music usecase initialization to
return error when feature is not enabled.
Not returning error was setting output configs to 0 or other
unexpected values, resulting in busy loops and other system errors.

Change-Id: I971b8c49cda407aff5b7986bc285f72e6b56cd99
1 file changed