ASoC: Fix SND_SOC_ALL_CODECS imply ac97 fallout

On i386 randconfig:

    sound/soc/codecs/wm9705.o: In function `wm9705_soc_resume':
    wm9705.c:(.text+0x128): undefined reference to `snd_ac97_reset'
    sound/soc/codecs/wm9712.o: In function `wm9712_soc_resume':
    wm9712.c:(.text+0x2d1): undefined reference to `snd_ac97_reset'
    sound/soc/codecs/wm9713.o: In function `wm9713_soc_resume':
    wm9713.c:(.text+0x820): undefined reference to `snd_ac97_reset'

Fix this by adding the missing dependencies on SND_SOC_AC97_BUS.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20200224112537.14483-1-geert@linux-m68k.org
Signed-off-by: Mark Brown <broonie@kernel.org>