avr32: Use platform_driver_probe for pio platform driver

The probe function of the pio platform driver lives in the init section
and so a pio device that is created after the init section is discarded
probably results in an oops.  Even if this cannot happen, using
platform_driver_probe is cleaner.  (If this can happen and should be
supported the probe function must live in the devinit section instead.)

Signed-off-by: Uwe Kleine-König <ukleinek@strlen.de>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

arch/avr32/mach-at32ap/pio.c

@@ -401,15 +401,14 @@ static int __init pio_probe(struct platform_device *pdev)
 }
 
 static struct platform_driver pio_driver = {
-	.probe		= pio_probe,
 	.driver		= {
 		.name		= "pio",
 	},
 };
 
 static int __init pio_init(void)
 {
-	return platform_driver_register(&pio_driver);
+	return platform_driver_probe(&pio_driver, pio_probe);
 }
 postcore_initcall(pio_init);