devlink: Move input checks from driver to devlink

Currently, all the input checks are done in driver.

After adding the split capability to devlink port, move the checks to
devlink.

Signed-off-by: Danielle Ratson <danieller@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>