This driver is useless if both SPI and I2C are not configured.
Thus don't build this driver if both SPI and I2C are not configured.

This patch silences below build warning if both SPI and I2C are not configured.

  CC      sound/soc/codecs/adav80x.o
sound/soc/codecs/adav80x.c:842:12: warning: 'adav80x_bus_probe' defined but not used [-Wunused-function]
sound/soc/codecs/adav80x.c:863:12: warning: 'adav80x_bus_remove' defined but not used [-Wunused-function]
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Acked-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@linaro.org>