mmc: mtk-sd: fix deferred probing

The driver overrides the error codes returned by platform_get_irq() to
-EINVAL, so if it returns -EPROBE_DEFER, the driver will fail the probe
permanently instead of the deferred probing. Switch to propagating the
error codes upstream.

Fixes: 20848903 ("mmc: mediatek: Add Mediatek MMC driver")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/20230617203622.6812-4-s.shtylyov@omp.ruSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/mtk-sd.c

@@ -2680,7 +2680,7 @@ static int msdc_drv_probe(struct platform_device *pdev)
 
 	host->irq = platform_get_irq(pdev, 0);
 	if (host->irq < 0) {
-		ret = -EINVAL;
+		ret = host->irq;
 		goto host_free;
 	}