Having this as a device_initcall() means that some real device drivers
can actually initialise _before_ the quirks are run, which is wrong.

We want it to run _before_ device_initcall(), but _after_ fs_initcall(),
since some arch-specific PCI initialisation like pcibios_assign_resources()
is done at fs_initcall().

We could use rootfs_initcall() but I actually want to use that for the
IOMMU initialisation, which has to come after the quirks, but still
before the real devices. So use fs_initcall_sync() instead -- since this
is entirely synchronous, it doesn't hurt that it'll escape the
synchronisation.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>