Update git submodules

* Update docs/submodules/storperf from branch 'stable/euphrates'
  - Update release notes

    Updates release notes for Euphrates
    * Changes in Sections
    * Tags not specified so used euphrates.1.0
    * Add details of logs' availability

    Change-Id: I6fe021a85aed03d033d34fb83b489ca24dc5950f
    JIRA: STORPERF-211
    Signed-off-by: Shrenik <shrenik.jain@research.iiit.ac.in>
    (cherry picked from commit 560181a755001c4f7d368c10cda8cd3316562f23)

diff --git a/docs/submodules/storperf b/docs/submodules/storperf
index 00e37ad..9a7975b 160000 (submodule)
--- a/docs/submodules/storperf
+++ b/docs/submodules/storperf
@@ -1 +1 @@
-Subproject commit 00e37adc0d2829c69d0309cdf7ec85907f97f91f
+Subproject commit 9a7975b7525ea078ebb7b2b3c5987577b650dc16