Update git submodules

* Update docs/submodules/vswitchperf from branch 'master'
  - Merge "driverctl: Add driverctl binding tool"
  - driverctl: Add driverctl binding tool

    Adds driverctl as a binding tool option for dpdk devices. JIRA
    ticket contains test results to verify it works when using
    dpdk-devbind or driverctl.

    JIRA: VSPERF-525

    Change-Id: Ia7a6e43a4b6fb3ba21f5d87d601f4ea4b95b7dab
    Signed-off-by: Christian Trautman <ctrautma@redhat.com>

diff --git a/docs/submodules/vswitchperf b/docs/submodules/vswitchperf
index a860c7b..1375b9e 160000 (submodule)
--- a/docs/submodules/vswitchperf
+++ b/docs/submodules/vswitchperf
@@ -1 +1 @@
-Subproject commit a860c7ba56ee9094e6f4607220a4baecbfc4e6e3
+Subproject commit 1375b9eff007b51af9b04b4c36975c39cc04cde8