ASoC: mediatek: add I2C dependency for CS42XX8

We should not select drivers that depend on I2C when that is disabled,
as it results in a build error:

warning: (SND_SOC_MT2701_CS42448) selects SND_SOC_CS42XX8_I2C which has unmet direct dependencies (SOUND && !M68K && !UML && SND && SND_SOC && I2C)
sound/soc/codecs/cs42xx8-i2c.c:60:1: warning: data definition has no type or storage class
 module_i2c_driver(cs42xx8_i2c_driver);
sound/soc/codecs/cs42xx8-i2c.c:60:1: error: type defaults to 'int' in declaration of 'module_i2c_driver' [-Werror=implicit-int]

Fixes: 1f458d53 ("ASoC: mediatek: Add mt2701-cs42448 driver and config option.")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>