[ARM] pxa: don't register lpd270 cpld_irq sysdev if !lpd270

Don't register the LPD270 cpld_irq system device when we're not running
on a LPD270 machine - "cpld_irq" is also registered (separately) by
Lubbock and Mainstone.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-pxa/lpd270.c

@@ -134,9 +134,12 @@ static struct sys_device lpd270_irq_device = {
 
 static int __init lpd270_irq_device_init(void)
 {
-	int ret = sysdev_class_register(&lpd270_irq_sysclass);
+	int ret = -ENODEV;
+	if (machine_is_logicpd_pxa270()) {
+		ret = sysdev_class_register(&lpd270_irq_sysclass);
 		if (ret == 0)
 			ret = sysdev_register(&lpd270_irq_device);
+	}
 	return ret;
 }