ASoC: SSM2602: Properly annotate i2c probe and remove functions

Annotate the i2c probe and remove functions with __devinit and __devexit.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>