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/sound/soc/fsl/pcm030-audio-fabric.c b/sound/soc/fsl/pcm030-audio-fabric.c
index b928ef7..6644cba 100644
--- a/sound/soc/fsl/pcm030-audio-fabric.c
+++ b/sound/soc/fsl/pcm030-audio-fabric.c
@@ -55,7 +55,7 @@
 	struct platform_device *pdev;
 	int rc;
 
-	if (!machine_is_compatible("phytec,pcm030"))
+	if (!of_machine_is_compatible("phytec,pcm030"))
 		return -ENODEV;
 
 	card.platform = &mpc5200_audio_dma_platform;