Update of VPP_STABLE_VER files and DPDK_STABLE_VER file

Update of VPP_STABLE_VER files and DPDK_STABLE_VER file

- use new vpp ref build - ubuntu 16.04:
  17.10-rc0~337-g2f9b0c0~b2873_amd64

- use new vpp ref build - centos7:
  17.10-rc0~337_g2f9b0c0~b2870.x86_64

- use new dpdk version>
  17.08-vpp1

- builds tested by semiweekly jobs:
  https://jenkins.fd.io/view/csit/job/csit-vpp-verify-master-ubuntu1604-semiweekly/73/
  https://jenkins.fd.io/view/csit/job/csit-vpp-verify-master-centos7-semiweekly/73/

Change-Id: I20245e50f5acf93af5d2f2bfae0307f7774f0c3b
Signed-off-by: Jan Gelety <jgelety@cisco.com>