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>