igbvf: fix unused external references

The igbvbf driver exposed several unused extrnal references due to the fact
that code was copied from igb and then some functionality was removed.
This changes that so that unused functions are either removed or made
static.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>