datapath: Introduce DirectRoutingDeviceRequired helper
datapath: Introduce DirectRoutingDeviceRequired helper

The Direct Routing Device is currently used by BPF Host
Routing and BPF Node Port. With both features, we don't
need it for tunneling mode. The DirectRoutingDeviceRequired
helper function checks the above conditions and returns if
the Direct Routing Device is required for the given
configuration.

Upcoming commits will fix several places that use Direct
Routing Device without tunneling or BPF Host Routing in
an account using DirectRoutingDeviceRequired.

Signed-off-by: Yutaro Hayakawa <65647db0e0f9a5caf65d28f8fe7f0278d9794968@isovalent.com>

michi-covalent/cilium,cilium/cilium,cilium/cilium,cilium/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,michi-covalent/cilium,michi-covalent/cilium