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/serial/apbuart.c b/drivers/serial/apbuart.c
index 0099b86..cc01c65 100644
--- a/drivers/serial/apbuart.c
+++ b/drivers/serial/apbuart.c
@@ -551,7 +551,7 @@
 /* OF Platform Driver                                                       */
 /* ======================================================================== */
 
-static int __devinit apbuart_probe(struct of_device *op,
+static int __devinit apbuart_probe(struct platform_device *op,
 				   const struct of_device_id *match)
 {
 	int i = -1;