usb: ulpi: make ops struct constant

None of the core ulpi functions perform any changes to the operations
struct, and logically as a struct that contains function pointers
there's no reason it shouldn't be constant.

Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Tal Shorer <tal.shorer@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/common/ulpi.c

@@ -202,7 +202,8 @@ static int ulpi_register(struct device *dev, struct ulpi *ulpi)
  * Allocates and registers a ULPI device and an interface for it. Called from
  * the USB controller that provides the ULPI interface.
  */
-struct ulpi *ulpi_register_interface(struct device *dev, struct ulpi_ops *ops)
+struct ulpi *ulpi_register_interface(struct device *dev,
+				     const struct ulpi_ops *ops)
 {
 	struct ulpi *ulpi;
 	int ret;

include/linux/ulpi/driver.h

@@ -15,7 +15,7 @@ struct ulpi_ops;
  */
 struct ulpi {
 	struct ulpi_device_id id;
-	struct ulpi_ops *ops;
+	const struct ulpi_ops *ops;
 	struct device dev;
 };
 

include/linux/ulpi/interface.h

@@ -16,7 +16,7 @@ struct ulpi_ops {
 	int (*write)(struct device *dev, u8 addr, u8 val);
 };
 
-struct ulpi *ulpi_register_interface(struct device *, struct ulpi_ops *);
+struct ulpi *ulpi_register_interface(struct device *, const struct ulpi_ops *);
 void ulpi_unregister_interface(struct ulpi *);
 
 #endif /* __LINUX_ULPI_INTERFACE_H */