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/watchdog/mpc8xxx_wdt.c b/drivers/watchdog/mpc8xxx_wdt.c
index 4cda64d..8fa213c 100644
--- a/drivers/watchdog/mpc8xxx_wdt.c
+++ b/drivers/watchdog/mpc8xxx_wdt.c
@@ -185,7 +185,7 @@
 	.fops	= &mpc8xxx_wdt_fops,
 };
 
-static int __devinit mpc8xxx_wdt_probe(struct of_device *ofdev,
+static int __devinit mpc8xxx_wdt_probe(struct platform_device *ofdev,
 				       const struct of_device_id *match)
 {
 	int ret;
@@ -238,7 +238,7 @@
 	return ret;
 }
 
-static int __devexit mpc8xxx_wdt_remove(struct of_device *ofdev)
+static int __devexit mpc8xxx_wdt_remove(struct platform_device *ofdev)
 {
 	mpc8xxx_wdt_pr_warn("watchdog removed");
 	del_timer_sync(&wdt_timer);