of: add 'of_' prefix to machine_is_compatible()

machine is compatible is an OF-specific call.  It should have
the of_ prefix to protect the global namespace.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Michal Simek <monstr@monstr.eu>

drivers/macintosh/windfarm_lm75_sensor.c

@@ -239,9 +239,9 @@ static struct i2c_driver wf_lm75_driver = {
 static int __init wf_lm75_sensor_init(void)
 {
 	/* Don't register on old machines that use therm_pm72 for now */
-	if (machine_is_compatible("PowerMac7,2") ||
-	    machine_is_compatible("PowerMac7,3") ||
-	    machine_is_compatible("RackMac3,1"))
+	if (of_machine_is_compatible("PowerMac7,2") ||
+	    of_machine_is_compatible("PowerMac7,3") ||
+	    of_machine_is_compatible("RackMac3,1"))
 		return -ENODEV;
 	return i2c_add_driver(&wf_lm75_driver);
 }