ice: move ice_set_vf_port_vlan near other .ndo ops

The ice_set_vf_port_vlan function is located in ice_sriov.c very far
away from the other .ndo operations that it is similar to. Move this so
that its located near the other .ndo operation definitions.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>