of: clk: Make of_clk_get_parent_{count,name}() parameter const

of_clk_get_parent_count() and of_clk_get_parent_name() never modify the
device nodes passed, so they can be const.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lkml.kernel.org/r/20200212094317.1150-1-geert+renesas@glider.beSigned-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/clk.c

@@ -4713,7 +4713,7 @@ EXPORT_SYMBOL(of_clk_get_by_name);
  *
  * Returns: The number of clocks that are possible parents of this node
  */
-unsigned int of_clk_get_parent_count(struct device_node *np)
+unsigned int of_clk_get_parent_count(const struct device_node *np)
 {
 	int count;
 
@@ -4725,7 +4725,7 @@ unsigned int of_clk_get_parent_count(struct device_node *np)
 }
 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
 
-const char *of_clk_get_parent_name(struct device_node *np, int index)
+const char *of_clk_get_parent_name(const struct device_node *np, int index)
 {
 	struct of_phandle_args clkspec;
 	struct property *prop;

include/linux/of_clk.h

@@ -11,17 +11,17 @@ struct of_device_id;
 
 #if defined(CONFIG_COMMON_CLK) && defined(CONFIG_OF)
 
-unsigned int of_clk_get_parent_count(struct device_node *np);
-const char *of_clk_get_parent_name(struct device_node *np, int index);
+unsigned int of_clk_get_parent_count(const struct device_node *np);
+const char *of_clk_get_parent_name(const struct device_node *np, int index);
 void of_clk_init(const struct of_device_id *matches);
 
 #else /* !CONFIG_COMMON_CLK || !CONFIG_OF */
 
-static inline unsigned int of_clk_get_parent_count(struct device_node *np)
+static inline unsigned int of_clk_get_parent_count(const struct device_node *np)
 {
 	return 0;
 }
-static inline const char *of_clk_get_parent_name(struct device_node *np,
+static inline const char *of_clk_get_parent_name(const struct device_node *np,
 						 int index)
 {
 	return NULL;