[ALSA] ASoC pxa2xx AC97 support

This patch adds pxa2xx AC97 ASoC audio support. It's based on
sound/arm/pxa-ac97 by Nicolas Pitre with the following differences.
 o Modified driver structure to use ASoC core PCM callbacks.
 o Removed AC97 configuration function (all handled in ASoC core)
 o Added and exported ASoC DAI configuration table.
 o Added DMA support for AUX DAC and Mic ADC
 o Separated out AC97 reset into cold and warm reset functions.
From: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>