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>
diff --git a/arch/powerpc/platforms/powermac/cpufreq_64.c b/arch/powerpc/platforms/powermac/cpufreq_64.c
index 708c751..3ed288e 100644
--- a/arch/powerpc/platforms/powermac/cpufreq_64.c
+++ b/arch/powerpc/platforms/powermac/cpufreq_64.c
@@ -398,11 +398,11 @@
 	int rc = -ENODEV;
 
 	/* Check supported platforms */
-	if (machine_is_compatible("PowerMac8,1") ||
-	    machine_is_compatible("PowerMac8,2") ||
-	    machine_is_compatible("PowerMac9,1"))
+	if (of_machine_is_compatible("PowerMac8,1") ||
+	    of_machine_is_compatible("PowerMac8,2") ||
+	    of_machine_is_compatible("PowerMac9,1"))
 		use_volts_smu = 1;
-	else if (machine_is_compatible("PowerMac11,2"))
+	else if (of_machine_is_compatible("PowerMac11,2"))
 		use_volts_vdnap = 1;
 	else
 		return -ENODEV;
@@ -729,9 +729,9 @@
 		return -ENODEV;
 	}
 
-	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"))
 		rc = g5_pm72_cpufreq_init(cpus);
 #ifdef CONFIG_PMAC_SMU
 	else