cx231xx_i2c_unregister
cx231xx_i2c_unregister(&dev->i2c_bus[2]);
cx231xx_i2c_unregister(&dev->i2c_bus[1]);
cx231xx_i2c_unregister(&dev->i2c_bus[0]);
void cx231xx_i2c_unregister(struct cx231xx_i2c *bus);