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/net/fs_enet/mii-fec.c b/drivers/net/fs_enet/mii-fec.c
index bddffd1..dbb9c48 100644
--- a/drivers/net/fs_enet/mii-fec.c
+++ b/drivers/net/fs_enet/mii-fec.c
@@ -101,7 +101,7 @@
 	return 0;
 }
 
-static int __devinit fs_enet_mdio_probe(struct of_device *ofdev,
+static int __devinit fs_enet_mdio_probe(struct platform_device *ofdev,
                                         const struct of_device_id *match)
 {
 	struct resource res;
@@ -192,7 +192,7 @@
 	return ret;
 }
 
-static int fs_enet_mdio_remove(struct of_device *ofdev)
+static int fs_enet_mdio_remove(struct platform_device *ofdev)
 {
 	struct mii_bus *bus = dev_get_drvdata(&ofdev->dev);
 	struct fec_info *fec = bus->priv;