i40e: Add allmulti support for the VF

This patch enables a feature to enable/disable all multicast
for a trusted VF.

Change-Id: I926eba7f8850c8d40f8ad7e08bbe4056bbd3985f
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>