[dts] [PATCH V3] test_plans/cvl_advanced_rss_pppoe: split pppoe case

[Tu, Lijuan]

> 1. split suite only pppoe cases is reserved, about vlan/esp/ah/l2tp/pfcp partial
> cases is split into a new suite(cvl_advanced_rss_vlan_esp_ah_l2tp_pfcp).
> 2. rename suite name.
> 
> Signed-off-by: Hailin Xu <hailinx.xu at intel.com>
> ---
> 
> v3:
>   - fix test plan build warning and errors in index.rst
> 
> v2:
>   - fix test plan build warning and errors
> 
> v1:
>   - split pppoe cases and rename suite name

Applied, thanks