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.c b/sound/soc/fsl/mpc5200_dma.c
index 1d4e716..3dcd146 100644
--- a/sound/soc/fsl/mpc5200_dma.c
+++ b/sound/soc/fsl/mpc5200_dma.c
@@ -369,7 +369,7 @@
 };
 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_platform);
 
-int mpc5200_audio_dma_create(struct of_device *op)
+int mpc5200_audio_dma_create(struct platform_device *op)
 {
 	phys_addr_t fifo;
 	struct psc_dma *psc_dma;
@@ -488,7 +488,7 @@
 }
 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_create);
 
-int mpc5200_audio_dma_destroy(struct of_device *op)
+int mpc5200_audio_dma_destroy(struct platform_device *op)
 {
 	struct psc_dma *psc_dma = dev_get_drvdata(&op->dev);