ALSA: hda - Move azx_first_init() into azx_probe_continue()

This is a preliminary work for the upcoming Haswell HDMI audio fixes.

azx_first_init() function can be safely called after the f/w loader,
since the f/w loader doesn't require the sound hardware initialization
beforehand.  Moving it into azx_probe_continue() cleans up the code
flow a bit.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>