ALSA: azt3328: add custom AC97 semi-emulation use standard ALSA AC97 layer

Make use of the very flexible ALSA ac97 layer (hooks for custom I/O!)
on this weird AC97 copycat hardware,
via semi-extended I/O translation/emulation.

Some 5kB binary/loaded size saved (well... additional huge AC97 module
penalty not factored in, of course ;-P).
Given that the driver previously had 20kB that's not bad,
but the much more important thing is to have AC97 layer stress-tested
with a thoroughly weird AC97 copycat (or, simply put, if it were not for
this AC97 test aspect, this effort would merely have been a nut job ;).
Signed-off-by: Andreas Mohr <andi@lisas.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/Kconfig

@@ -152,10 +152,16 @@ config SND_AZT3328
 	select SND_MPU401_UART
 	select SND_PCM
 	select SND_RAWMIDI
+	select SND_AC97_CODEC
 	help
 	  Say Y here to include support for Aztech AZF3328 (PCI168)
 	  soundcards.
 
+	  Supported features: AC97-"conformant" mixer, MPU401/OPL3, analog I/O
+	  (16bit/8bit, many sample rates [<= 66.2kHz], NO hardware mixing),
+	  Digital Enhanced Game Port, 1.024MHz multimedia sequencer timer,
+	  ext. codec (I2S port), onboard amp (4W/4Ohms/ch), suspend/resume.
+
 	  To compile this driver as a module, choose M here: the module
 	  will be called snd-azt3328.