mmc: atmel-mci: Add missing clk_disable_unprepare()

The error path when atmci_configure_dma() set dma fails in atmci driver
does not correctly disable the clock.
Add the missing clk_disable_unprepare() to the error path for pair with
clk_prepare_enable().

Fixes: 467e081 ("mmc: atmel-mci: use probe deferring if dma controller is not ready yet")
Signed-off-by: Gu Bowen <gubowen5@huawei.com>
Acked-by: Aubin Constans <aubin.constans@microchip.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250225022856.3452240-1-gubowen5@huawei.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/atmel-mci.c

@@ -2499,8 +2499,10 @@ static int atmci_probe(struct platform_device *pdev)
 	/* Get MCI capabilities and set operations according to it */
 	atmci_get_cap(host);
 	ret = atmci_configure_dma(host);
-	if (ret == -EPROBE_DEFER)
+	if (ret == -EPROBE_DEFER) {
+		clk_disable_unprepare(host->mck);
 		goto err_dma_probe_defer;
+	}
 	if (ret == 0) {
 		host->prepare_data = &atmci_prepare_data_dma;
 		host->submit_data = &atmci_submit_data_dma;