[PNPBIOS] disable if ACPI is active

As further ACPI pnp functionaility is implemented it is no longer
safe to run ACPI and PNPBIOS concurrently.

We therefore take the following approach:
- attempt to enable ACPI support
- if ACPI fails (blacklist etc.) enable pnpbios support
- if ACPI support is not compiled in the kernel enable pnpbios support
Signed-off-by: Adam Belay <ambx1@neo.rr.com>

drivers/pnp/pnpbios/core.c

@@ -538,6 +538,12 @@ int __init pnpbios_init(void)
 		return -ENODEV;
 	}
 
+	if (!acpi_disabled) {
+		pnpbios_disabled = 1;
+		printk(KERN_INFO "PnPBIOS: Disabled by ACPI\n");
+		return -ENODEV;
+	}
+
 	/* scan the system for pnpbios support */
 	if (!pnpbios_probe_system())
 		return -ENODEV;