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/scsi/qlogicpti.h b/drivers/scsi/qlogicpti.h
index e3c74d1..4377e87 100644
--- a/drivers/scsi/qlogicpti.h
+++ b/drivers/scsi/qlogicpti.h
@@ -342,7 +342,7 @@
 	u_int	                  req_in_ptr;		/* index of next request slot */
 	u_int	                  res_out_ptr;		/* index of next result slot  */
 	long	                  send_marker;		/* must we send a marker?     */
-	struct of_device	 *op;
+	struct platform_device	 *op;
 	unsigned long		  __pad;
 
 	int                       cmd_count[MAX_TARGETS];