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/usb/host/ehci-ppc-of.c b/drivers/usb/host/ehci-ppc-of.c
index 5aec928..335ee69 100644
--- a/drivers/usb/host/ehci-ppc-of.c
+++ b/drivers/usb/host/ehci-ppc-of.c
@@ -106,7 +106,7 @@
 
 
 static int __devinit
-ehci_hcd_ppc_of_probe(struct of_device *op, const struct of_device_id *match)
+ehci_hcd_ppc_of_probe(struct platform_device *op, const struct of_device_id *match)
 {
 	struct device_node *dn = op->dev.of_node;
 	struct usb_hcd *hcd;
@@ -210,7 +210,7 @@
 }
 
 
-static int ehci_hcd_ppc_of_remove(struct of_device *op)
+static int ehci_hcd_ppc_of_remove(struct platform_device *op)
 {
 	struct usb_hcd *hcd = dev_get_drvdata(&op->dev);
 	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
@@ -253,7 +253,7 @@
 }
 
 
-static int ehci_hcd_ppc_of_shutdown(struct of_device *op)
+static int ehci_hcd_ppc_of_shutdown(struct platform_device *op)
 {
 	struct usb_hcd *hcd = dev_get_drvdata(&op->dev);