rtc: st-lpc: Release some resources in st_rtc_probe() in case of error

If an error occurs after clk_get(), the corresponding resources should be
released.

Use devm_clk_get() to fix it.

Fixes: b5b2bdf ("rtc: st: Add new driver for ST's LPC RTC")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/866af6adbc7454a7b4505eb6c28fbdc86ccff39e.1686251455.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: tititiou36

drivers/rtc/rtc-st-lpc.c

@@ -228,7 +228,7 @@ static int st_rtc_probe(struct platform_device *pdev)
 	enable_irq_wake(rtc->irq);
 	disable_irq(rtc->irq);
 
-	rtc->clk = clk_get(&pdev->dev, NULL);
+	rtc->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(rtc->clk)) {
 		dev_err(&pdev->dev, "Unable to request clock\n");
 		return PTR_ERR(rtc->clk);