rocker: introduce rocker switch driver This patch introduces the first driver to benefit from the switchdev infrastructure and to implement newly introduced switch ndos. This is a driver for emulated switch chip implemented in qemu: https://github.com/sfeldma/qemu-rocker/ This patch is a result of joint work with Scott Feldman. Signed-off-by: Scott Feldman <[email protected]> Signed-off-by: Jiri Pirko <[email protected]> Reviewed-by: Thomas Graf <[email protected]> Reviewed-by: John Fastabend <[email protected]> Signed-off-by: David S. Miller <[email protected]>