net/ixgbe: support power management on VF

net/ixgbe: support power management on VF

When .get_monitor_addr API was introduced, it was implemented in the
ixgbe driver, but only for the physical function; the virtual function
portion of the driver does not support that API.

Add the missing function pointer to VF device structure.

Fixes: 3982b7967bb7 ("net/ixgbe: implement power management API")
Cc: stable@dpdk.org
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Reviewed-by: David Hunt <david.hunt@intel.com>
Acked-by: Haiyue Wang <haiyue.wang@intel.com>