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/macintosh/therm_adt746x.c b/drivers/macintosh/therm_adt746x.c
index c42eeb4..d0d2213 100644
--- a/drivers/macintosh/therm_adt746x.c
+++ b/drivers/macintosh/therm_adt746x.c
@@ -84,7 +84,7 @@
 
 static enum {ADT7460, ADT7467} therm_type;
 static int therm_bus, therm_address;
-static struct of_device * of_dev;
+static struct platform_device * of_dev;
 static struct thermostat* thermostat;
 static struct task_struct *thread_therm = NULL;