of/device: Replace struct of_device with struct platform_device

of_device is just an alias for platform_device, so remove it entirely.  Also
replace to_of_device() with to_platform_device() and update comment blocks.

This patch was initially generated from the following semantic patch, and then
edited by hand to pick up the bits that coccinelle didn't catch.

@@
@@
-struct of_device
+struct platform_device

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Reviewed-by: David S. Miller <davem@davemloft.net>
diff --git a/sound/soc/fsl/mpc5200_dma.h b/sound/soc/fsl/mpc5200_dma.h
index e1ec6d9..ca99586 100644
--- a/sound/soc/fsl/mpc5200_dma.h
+++ b/sound/soc/fsl/mpc5200_dma.h
@@ -81,8 +81,8 @@
 	return &psc_dma->playback;
 }
 
-int mpc5200_audio_dma_create(struct of_device *op);
-int mpc5200_audio_dma_destroy(struct of_device *op);
+int mpc5200_audio_dma_create(struct platform_device *op);
+int mpc5200_audio_dma_destroy(struct platform_device *op);
 
 extern struct snd_soc_platform mpc5200_audio_dma_platform;