ALSA: ASoC: AC97 codec PM

Simple suspend/resume for AC97 ASoC codec.

Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Acked-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>