clk: Add clk_hw_unregister_composite helper function definition

This function has been delcared but not defined anywhere. Hence, this
commit adds definition for it.

Fixes: 49cb392d36 ("clk: composite: Add hw based registration APIs")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lkml.kernel.org/r/20191115162901.17456-3-manivannan.sadhasivam@linaro.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/clk-composite.c

@@ -343,3 +343,14 @@ void clk_unregister_composite(struct clk *clk)
 	clk_unregister(clk);
 	kfree(composite);
 }
+
+void clk_hw_unregister_composite(struct clk_hw *hw)
+{
+	struct clk_composite *composite;
+
+	composite = to_clk_composite(hw);
+
+	clk_hw_unregister(hw);
+	kfree(composite);
+}
+EXPORT_SYMBOL_GPL(clk_hw_unregister_composite);