net/mlx5: E-Switch: Fix using fwd and modify when firmware doesn't support it

Currently, if firmware doesn't support fwd and modify, driver fails
initializing eswitch chains while entering switchdev mode.

Instead, on such cases, disable the chains and prio feature (as we can't
restore the chain on miss) and the usage of fwd and modify.

Fixes: 8f1e0b97 ("net/mlx5: E-Switch, Mark miss packets with new chain id mapping")
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Oz Shlomo <ozsh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>