ASoC: hdac_hdmi: Fix codec power state in S3 during playback

If the system enters S3 during a playback, codec power needs to
be turned OFF during suspend and restored during resume. With
this patch the AFG node is set to D3 and codec power is turned
OFF during controller suspend call.

During resume, the codec power is left in ON state if the
playback was in progress while suspending.

Also setting power state for AFG node is optimized. With this the
loop with timeout is removed and codec_read is used instead.

Signed-off-by: Subhransu S. Prusty <subhransu.s.prusty@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>