i40e: Make VF resets more reliable

Clear the VFLR bit immediately after triggering a reset instead of
waiting until after cleanup is complete. Make sure to trigger a reset
every time, not just if the PF is up.

These changes fix a problem where VF resets would get lost by the PF,
preventing the VF driver from initializing.

Change-ID: I5945cf2884095b7b0554867c64df8617e71d9d29
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>