Add device start/stop functions for DSA devices bound to vfio. For devices bound to the IDXD kernel driver, these are not required since the IDXD kernel driver takes care of this. Signed-off-by: Bruce Richardson <bruce.richardson@intel.com> Signed-off-by: Kevin Laatz <kevin.laatz@intel.com> Reviewed-by: Conor Walsh <conor.walsh@intel.com>