Update git submodules

Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Add spec cpu2006 test case"
  - Add spec cpu2006 test case

    JIRA: YARDSTICK-764

    This work is about support run SPEC CPU2006 benchmark.

    users must get a "cpu2006-1.2.iso" from the SPEC website,
    save it under the /home/opnfv/yardstick/yardstick/resources folder
    (e.g. /home/opnfv/yardstick/yardstick/resources/cpu2006-1.2.iso),
    user may also supply a runspec cfg file
    (e.g. /home/opnfv/yardstick/yardstick/resources/files/yardstick_spec_cpu2006.cfg).

    Change-Id: If4aecc1c14635a07589555196d2edc8bd37d7bdb
    Signed-off-by: JingLu5 <lvjing5@huawei.com>