gve: Add flow steering device option

Add a new device option to signal to the driver that the device supports
flow steering. This device option also carries the maximum number of
flow steering rules that the device can store.

Signed-off-by: Jeroen de Borst <jeroendb@google.com>
Co-developed-by: Ziwei Xiao <ziweixiao@google.com>
Signed-off-by: Ziwei Xiao <ziweixiao@google.com>
Reviewed-by: Praveen Kaligineedi <pkaligineedi@google.com>
Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20240625001232.1476315-4-ziweixiao@google.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>