Update git submodules

Update git submodules

* Update docs/submodules/vswitchperf from branch 'master'
  - Merge "sriov: Determine path to the bind-tool"
  - sriov: Determine path to the bind-tool

    In case of SRIOV path to the bind-tool must be known before
    NIC driver is re-initialized. It means before TestCase.__init__()
    is called.

    Change-Id: Ib6fdba233e665144510dd492462c0a21aa19ed71
    Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
    Reviewed-by: Al Morton <acmorton@att.com>
    Reviewed-by: Christian Trautman <ctrautma@redhat.com>
    Reviewed-by: Sridhar Rao <sridhar.rao@spirent.com>
    Reviewed-by: Trevor Cooper <trevor.cooper@intel.com>