sfc: receive packets from EF100 VFs into representors

If the source m-port of a packet in __ef100_rx_packet() is a VF,
 hand off the packet to the corresponding representor with
 efx_ef100_rep_rx_packet().

Signed-off-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>