cx23885_i2c_unregister
cx23885_i2c_unregister(&dev->i2c_bus[2]);
cx23885_i2c_unregister(&dev->i2c_bus[1]);
cx23885_i2c_unregister(&dev->i2c_bus[0]);
extern int cx23885_i2c_unregister(struct cx23885_i2c *bus);