ASoC: cs53l30: Use the devm_clk_get_optional() helper

Use devm_clk_get_optional() instead of hand writing it.
This saves some LoC and improves the semantic.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/3219effee5c7f190530bdb1ef8ec35cb142e3611.1684594433.git.christophe.jaillet@wanadoo.frSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/cs53l30.c

@@ -990,15 +990,11 @@ static int cs53l30_i2c_probe(struct i2c_client *client)
 	}
 
 	/* Check if MCLK provided */
-	cs53l30->mclk = devm_clk_get(dev, "mclk");
+	cs53l30->mclk = devm_clk_get_optional(dev, "mclk");
 	if (IS_ERR(cs53l30->mclk)) {
-		if (PTR_ERR(cs53l30->mclk) != -ENOENT) {
 		ret = PTR_ERR(cs53l30->mclk);
 		goto error;
 	}
-		/* Otherwise mark the mclk pointer to NULL */
-		cs53l30->mclk = NULL;
-	}
 
 	/* Fetch the MUTE control */
 	cs53l30->mute_gpio = devm_gpiod_get_optional(dev, "mute",