Reorder HDMI audio enabling sequence so that
1) the sink knows about the coming audio stream
2) unmute
3) start transferring audio samples
The theory is that in the path A=>B=>C, we first make C ready, and then
enable B, and lastly allow A to send audio samples.
Signed-off-by: Wu Fengguang <wfg@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>