Update git submodules

* Update docs/submodules/vswitchperf from branch 'master'
  - Merge "LTD: Expand requirements of Soak/Long Duration Tests"
  - LTD: Expand requirements of Soak/Long Duration Tests

    In Project discussion on Jan 17, 2018 including review of RFC 8204,
    we identified the following five areas to improve the Soak tests.
    See the JIRA ticket for details.

    JIRA: VSPERF-557

    Change-Id: I5314c283a383c57d99863fcf7262c4f28e1c12a8
    Signed-off-by: Al Morton <acmorton@att.com>
    Reviewed-by: Martin Klozik <martinx.klozik@intel.com>
    Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>
    Reviewed-by: Christian Trautman <ctrautma@redhat.com>
    Reviewed-by: Sridhar Rao <sridhar.rao@spirent.com>
    Reviewed-by: Trevor Cooper <trevor.cooper@intel.com>
    Reviewed-by: Richard Elias <richardx.elias@intel.com>

diff --git a/docs/submodules/vswitchperf b/docs/submodules/vswitchperf
index b8ef508..0638565 160000 (submodule)
--- a/docs/submodules/vswitchperf
+++ b/docs/submodules/vswitchperf
@@ -1 +1 @@
-Subproject commit b8ef508a78181e017071d9189bb0030305fd1080
+Subproject commit 06385651cf8d5db946b800a94f2453c11114f973