spi: Provide defer reason if getting irq during probe fails

Using dev_err_probe() in spi_probe() improves the kernel output from

	spi spi0.0: deferred probe pending: (reason unknown)

to

	spi spi0.0: deferred probe pending: ad7124: Failed to get irq...

for my current quest to make a certain spi device work.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20241004094234.268301-2-u.kleine-koenig@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: Uwe Kleine-König

drivers/spi/spi.c

@@ -419,7 +419,7 @@ static int spi_probe(struct device *dev)
 	if (dev->of_node) {
 		spi->irq = of_irq_get(dev->of_node, 0);
 		if (spi->irq == -EPROBE_DEFER)
-			return -EPROBE_DEFER;
+			return dev_err_probe(dev, -EPROBE_DEFER, "Failed to get irq\n");
 		if (spi->irq < 0)
 			spi->irq = 0;
 	}