sfc: add devlink support for ef100

Add devlink infrastructure support. Further patches add devlink
info and devlink port support.

Signed-off-by: Alejandro Lucero <alejandro.lucero-palau@amd.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Acked-by: Martin Habets <habetsm.xilinx@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>