clk: Constify struct clk_init_data

Allow drivers to declare their clk_init_data const, the framework really
shouldn't be modifying the data.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

include/linux/clk-provider.h

@@ -144,7 +144,7 @@ struct clk_init_data {
  */
 struct clk_hw {
 	struct clk *clk;
-	struct clk_init_data *init;
+	const struct clk_init_data *init;
 };
 
 /*