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/ibm_newemac/tah.h b/drivers/net/ibm_newemac/tah.h
index a068b56..61dbeca 100644
--- a/drivers/net/ibm_newemac/tah.h
+++ b/drivers/net/ibm_newemac/tah.h
@@ -48,7 +48,7 @@
 	int				users;
 
 	/* OF device instance */
-	struct of_device		*ofdev;
+	struct platform_device		*ofdev;
 };
 
 
@@ -74,11 +74,11 @@
 
 extern int tah_init(void);
 extern void tah_exit(void);
-extern int tah_attach(struct of_device *ofdev, int channel);
-extern void tah_detach(struct of_device *ofdev, int channel);
-extern void tah_reset(struct of_device *ofdev);
-extern int tah_get_regs_len(struct of_device *ofdev);
-extern void *tah_dump_regs(struct of_device *ofdev, void *buf);
+extern int tah_attach(struct platform_device *ofdev, int channel);
+extern void tah_detach(struct platform_device *ofdev, int channel);
+extern void tah_reset(struct platform_device *ofdev);
+extern int tah_get_regs_len(struct platform_device *ofdev);
+extern void *tah_dump_regs(struct platform_device *ofdev, void *buf);
 
 #else