clk: use match_string() helper

match_string() returns the index of an array for a matching string,
which can be used instead of open coded variant.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: linux-clk@vger.kernel.org
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/clk.c

@@ -2170,7 +2170,6 @@ void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
 bool clk_has_parent(struct clk *clk, struct clk *parent)
 {
 	struct clk_core *core, *parent_core;
-	unsigned int i;
 
 	/* NULL clocks should be nops, so return success if either is NULL. */
 	if (!clk || !parent)
@@ -2183,11 +2182,8 @@ bool clk_has_parent(struct clk *clk, struct clk *parent)
 	if (core->parent == parent_core)
 		return true;
 
-	for (i = 0; i < core->num_parents; i++)
-		if (strcmp(core->parent_names[i], parent_core->name) == 0)
-			return true;
-
-	return false;
+	return match_string(core->parent_names, core->num_parents,
+			    parent_core->name) >= 0;
 }
 EXPORT_SYMBOL_GPL(clk_has_parent);