This support is completely duplicated in the initramfs code.  As things
stand we attempt this PNP when we do not have the devices we could use
loaded and will not be able to load until the initramfs is loaded.

Therefore disable this support in the kernel and rely on the
initramfs-tools code.

BugLink: http://bugs.launchpad.net/bugs/1259861Signed-off-by: Andy Whitcroft <apw@canonical.com>