VFIO may be used by buses other than PCI. This patch enables
the VFIO on the basis of vfio root presence.
Since vfio_enable should be called only once, pci_vfio_enable
is also removed.
A debug print is added in case vfio_pci module is not present.
Signed-off-by: Hemant Agrawal <hemant.agrawal@nxp.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>