ASoC: Use finer grained dependencies in SND_SOC_ALL_CODECS

Move the bus dependencies in SND_SOC_ALL_CODECS into the individual
codec options rather than have them centrally. This allows the
inclusion of AC97 codecs when testing on platforms with AC97 support
and will also handle codecs on multi-function devices more gracefully.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>