ARM: shmobile: only select sound drivers that build

ARM: shmobile: only select sound drivers that build

A couple of codec drivers are selected by shmobile platform code,
but depend on I2C, which results in a build error:

sound/soc/codecs/ak4642.c:638:1: warning: data definition has no type or storage class
 module_i2c_driver(ak4642_i2c_driver);
 ^
sound/soc/codecs/ak4642.c:638:1: error: type defaults to 'int' in declaration of 'module_i2c_driver' [-Werror=implicit-int]
sound/soc/codecs/ak4642.c:638:1: warning: parameter names (without types) in function declaration
sound/soc/codecs/ak4642.c:627:26: warning: 'ak4642_i2c_driver' defined but not used [-Wunused-variable]

This ensures that we do not enable the respective drivers when I2C
is disabled.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>