ixgbe: rework ixgbe MTA handling to not drop packets

This change modifies the ixgbe drivers so that it will not drop the
multicast filters while updating them.  Instead it uses an intermediate
table to store the filter and then writes that filter to the hardware.

Based on original patch from Dave Boutcher <daveboutcher@gmail.com>

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Reported-by: Dave Boutcher <daveboutcher@gmail.com>
Tested-by: Stephen Ko <stephen.s.ko@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>