sfc: Remove falcon references

Siena was using functions from the Falcon architecture.
These start with the efx_farch prefix.
Now that both of these are in separate modules the references
are no longer used in the sfc.ko module.

Signed-off-by: Martin Habets <habetsm.xilinx@gmail.com>
Acked-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>