video: fbdev: pxa3xx_gcu: fix error return code in pxa3xx_gcu_probe()

platform_get_irq() returns an error code, but the pxa3xx_gcu driver
ignores it and always returns -ENODEV. This is not correct and,
prevents -EPROBE_DEFER from being propagated properly.

Also, notice that platform_get_irq() no longer returns 0 on error:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e330b9a6bb35dc7097a4f02cb1ae7b6f96df92af

Print and propagate the return value of platform_get_irq on failure.

This issue was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

drivers/video/fbdev/pxa3xx-gcu.c

@@ -626,8 +626,8 @@ static int pxa3xx_gcu_probe(struct platform_device *pdev)
 	/* request the IRQ */
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
-		dev_err(dev, "no IRQ defined\n");
-		return -ENODEV;
+		dev_err(dev, "no IRQ defined: %d\n", irq);
+		return irq;
 	}
 
 	ret = devm_request_irq(dev, irq, pxa3xx_gcu_handle_irq,