clk: Constify clk_has_parent()

clk_has_parent() doesn't modify the clocks being passed, so let's make
it const.

Suggested-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220816112530.1837489-21-maxime@cerno.tech
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/clk.c

@@ -2593,7 +2593,7 @@ void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
  *
  * Returns true if @parent is a possible parent for @clk, false otherwise.
  */
-bool clk_has_parent(struct clk *clk, struct clk *parent)
+bool clk_has_parent(const struct clk *clk, const struct clk *parent)
 {
 	/* NULL clocks should be nops, so return success if either is NULL. */
 	if (!clk || !parent)

include/linux/clk.h

@@ -799,7 +799,7 @@ int clk_set_rate_exclusive(struct clk *clk, unsigned long rate);
  *
  * Returns true if @parent is a possible parent for @clk, false otherwise.
  */
-bool clk_has_parent(struct clk *clk, struct clk *parent);
+bool clk_has_parent(const struct clk *clk, const struct clk *parent);
 
 /**
  * clk_set_rate_range - set a rate range for a clock source