i2c-sibyte: Mark i2c_sibyte_add_bus() as static

The i2c_sibyte_add_bus() function is not called, nor meant to, from 
outside, so mark it as static; fixing a sparse warning too.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

drivers/i2c/busses/i2c-sibyte.c

@@ -132,7 +132,7 @@ static const struct i2c_algorithm i2c_sibyte_algo = {
 /*
  * registering functions to load algorithms at runtime
  */
-int __init i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed)
+static int __init i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed)
 {
 	struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;