Update git submodules

* Update docs/submodules/vswitchperf from branch 'master'
  - Merge "Fix packages for SLES15"
  - Fix packages for SLES15

    Change-Id: Id01c4f76c146a0f0630bf1926ece48aabff0bfa1
    Signed-off-by: Jose Lausuch <jalausuch@suse.com>

diff --git a/docs/submodules/vswitchperf b/docs/submodules/vswitchperf
index 0236fe3..a87a769 160000 (submodule)
--- a/docs/submodules/vswitchperf
+++ b/docs/submodules/vswitchperf
@@ -1 +1 @@
-Subproject commit 0236fe345f85faf5e07fae683106021c97490720
+Subproject commit a87a7696e58082b10fadef24176d53ebc67f3bd5