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>
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index c1c23b9..4a0b483 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -312,6 +312,8 @@
  */
 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);