[V3] app/testpmd: restore VXLAN-GPE support

[Ferruh Yigit]

On 7/23/2024 3:26 PM, Gavin Li wrote:
> VXLAN-GPE support was removed from testpmd recently. Drivers which are
> not migrated are still using VXLAN-GPE in tests.
> 
> This commit is to restore the support for VXLAN-GPE in testpmd.
> 
> After this change, there are two command line items with the same name, ie.
> "protocol". One is for the new VXLAN extensions and the other is for the
> deprecated VXLAN-GPE. Add a new one that is more obvious for the new VXLAN
> structure since the two have different command line context.
> 
> Fixes: da118115d95c ("app/testpmd: support matching any VXLAN field")
> Signed-off-by: Gavin Li <gavinl at nvidia.com>
>

Ack, let me do checks on it, I am for getting this for -rc3 if we can.