Update git submodules

* Update docs/submodules/daisy from branch 'stable/euphrates'
  - Add -allow-limited-size to mkisofs

    Otherwise, we encountered:
    File target/el7/noarch/opnfv-2017-10-11_09-58-21.bin is larger than 4GiB-1.
    -allow-limited-size was not specified. There is no way do represent this file size. Aborting.

    Change-Id: Ied43c9e0c0e635ff52740c18b3b3001a4e6a3604
    Signed-off-by: Zhijiang Hu <hu.zhijiang@zte.com.cn>
    (cherry picked from commit 3580a4c2bf8596dc94ab92619b6185757725f566)

diff --git a/docs/submodules/daisy b/docs/submodules/daisy
index e45eda9..2e4c5f1 160000 (submodule)
--- a/docs/submodules/daisy
+++ b/docs/submodules/daisy
@@ -1 +1 @@
-Subproject commit e45eda9887381c70afc26aa45b0cf9ce16bf0398
+Subproject commit 2e4c5f1505701ce94a02b2060ea5b0e87c493e29