ALSA: hda - Migrate hdac_stream into legacy driver

Embed hdac_stream object into azx_dev, and use a few basic helper
functions.  The most of helper codes for hdac_stream aren't still used
yet.

Also this commit disables the tracepoints temporarily due to build
problems.  It'll be enabled again later.

Signed-off-by: Takashi Iwai <tiwai@suse.de>