clk: Provide dummy clk_unregister()

While there's no actual implementation behind it having the call to use
in drivers makes them feel neater from a driver author point of view. An
actual implementation can wait for someone who needs to use the function
in a real system.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
[mturquette@linaro.org: void return type instead of int -EINVAL]
Signed-off-by: Mike Turquette <mturquette@linaro.org>

drivers/clk/clk.c

@@ -1420,6 +1420,15 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw)
 }
 EXPORT_SYMBOL_GPL(clk_register);
 
+/**
+ * clk_unregister - unregister a currently registered clock
+ * @clk: clock to unregister
+ *
+ * Currently unimplemented.
+ */
+void clk_unregister(struct clk *clk) {}
+EXPORT_SYMBOL_GPL(clk_unregister);
+
 /***        clk rate change notifiers        ***/
 
 /**

include/linux/clk-provider.h

@@ -312,6 +312,8 @@ struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
  */
 struct clk *clk_register(struct device *dev, struct clk_hw *hw);
 
+void clk_unregister(struct clk *clk);
+
 /* helper functions */
 const char *__clk_get_name(struct clk *clk);
 struct clk_hw *__clk_get_hw(struct clk *clk);