dmclock: update dmclock submodule sha1 to tip of ceph/dmclock.git master

This update will fix the build of Ceph when -DWITH_TESTS=OFF is used.

Signed-off-by: Ricardo Dias <rdias@suse.com>

diff --git a/src/dmclock b/src/dmclock
index 27aa51f564d1b9c1b4d0f63b28cdea17c188ec5c..5c82208802340fe240032f16604b0f9961247849 160000 (submodule)
--- a/src/dmclock
+++ b/src/dmclock
@@ -1 +1 @@
-Subproject commit 27aa51f564d1b9c1b4d0f63b28cdea17c188ec5c
+Subproject commit 5c82208802340fe240032f16604b0f9961247849