ALSA: hda - Shutdown CX20722 on reboot/free to avoid spurious noises

On shutdown/reboot of CX20722, first shut down all EAPDs, then
shut down the afg node to D3.

Failure to do so can lead to spurious noises from the internal speaker
directly after reboot (and before the codec is reinitialized again, i e
in BIOS setup or GRUB menus).

BugLink: https://bugs.launchpad.net/bugs/1487345


Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>