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/sbus/char/display7seg.c b/drivers/sbus/char/display7seg.c
index 47db975..1690e53 100644
--- a/drivers/sbus/char/display7seg.c
+++ b/drivers/sbus/char/display7seg.c
@@ -170,7 +170,7 @@
 	.fops		= &d7s_fops
 };
 
-static int __devinit d7s_probe(struct of_device *op,
+static int __devinit d7s_probe(struct platform_device *op,
 			       const struct of_device_id *match)
 {
 	struct device_node *opts;
@@ -236,7 +236,7 @@
 	goto out;
 }
 
-static int __devexit d7s_remove(struct of_device *op)
+static int __devexit d7s_remove(struct platform_device *op)
 {
 	struct d7s *p = dev_get_drvdata(&op->dev);
 	u8 regs = readb(p->regs);