i40e: Fix Error I40E_AQ_RC_EINVAL when removing VFs

When removing VFs for PF added to bridge there was
an error I40E_AQ_RC_EINVAL. It was caused by not properly
resetting and reinitializing PF when adding/removing VFs.
Changed how reset is performed when adding/removing VFs
to properly reinitialize PFs VSI.

Fixes: fc60861e ("i40e: start up in VEPA mode by default")
Signed-off-by: Sylwester Dziedziuch <sylwesterx.dziedziuch@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>