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/drivers/video/xilinxfb.c b/drivers/video/xilinxfb.c
index 29b5daa..0c9ce88 100644
--- a/drivers/video/xilinxfb.c
+++ b/drivers/video/xilinxfb.c
@@ -397,7 +397,7 @@
  */
 
 static int __devinit
-xilinxfb_of_probe(struct of_device *op, const struct of_device_id *match)
+xilinxfb_of_probe(struct platform_device *op, const struct of_device_id *match)
 {
 	const u32 *prop;
 	u32 *p;
@@ -477,7 +477,7 @@
 	return -ENODEV;
 }
 
-static int __devexit xilinxfb_of_remove(struct of_device *op)
+static int __devexit xilinxfb_of_remove(struct platform_device *op)
 {
 	return xilinxfb_release(&op->dev);
 }