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_psc_ac97.c b/sound/soc/fsl/mpc5200_psc_ac97.c
index e2ee220..a031017 100644
--- a/sound/soc/fsl/mpc5200_psc_ac97.c
+++ b/sound/soc/fsl/mpc5200_psc_ac97.c
@@ -263,7 +263,7 @@
  * - Probe/remove operations
  * - OF device match table
  */
-static int __devinit psc_ac97_of_probe(struct of_device *op,
+static int __devinit psc_ac97_of_probe(struct platform_device *op,
 				      const struct of_device_id *match)
 {
 	int rc, i;
@@ -303,7 +303,7 @@
 	return 0;
 }
 
-static int __devexit psc_ac97_of_remove(struct of_device *op)
+static int __devexit psc_ac97_of_remove(struct platform_device *op)
 {
 	return mpc5200_audio_dma_destroy(op);
 }