doc: update i40e tuning in linux guide
doc: update i40e tuning in linux guide

Updated the i40e Enabling Additional Functionality
section (5.7) of DPDK Getting Started Guide.

Signed-off-by: Siobhan Butler <8cf2da75f16c15b95e66f52a35c85d9ba5dc91d6@intel.com>
Signed-off-by: Helin Zhang <aba9dfdb1a6ec8bf1ff66b95272c029f8dfde1b1@intel.com>
Acked-by: Bernard Iremonger <233eeff376ad0c06f66f06c5522ea3c4feb30d3b@intel.com>

phermansson/dpdk,phermansson/dpdk,phermansson/dpdk,phermansson/dpdk