trace-cmd: Add Developer's Certificate of Origin document "DCO"

To formalize exactly what a Signed-off-by means in a commit log, add the DCO
document that explains it.

Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
diff --git a/DCO b/DCO
new file mode 100644
index 0000000..775c110
--- /dev/null
+++ b/DCO
@@ -0,0 +1,47 @@
+
+(Copied from the Linux Kernel's Documentation/process/submitting-patches.rst)
+
+Sign your work - the Developer's Certificate of Origin
+------------------------------------------------------
+
+The sign-off is a simple line at the end of the explanation for the
+patch, which certifies that you wrote it or otherwise have the right to
+pass it on as an open-source patch.  The rules are pretty simple: if you
+can certify the below:
+
+Developer's Certificate of Origin 1.1
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+By making a contribution to this project, I certify that:
+
+        (a) The contribution was created in whole or in part by me and I
+            have the right to submit it under the open source license
+            indicated in the file; or
+
+        (b) The contribution is based upon previous work that, to the best
+            of my knowledge, is covered under an appropriate open source
+            license and I have the right under that license to submit that
+            work with modifications, whether created in whole or in part
+            by me, under the same open source license (unless I am
+            permitted to submit under a different license), as indicated
+            in the file; or
+
+        (c) The contribution was provided directly to me by some other
+            person who certified (a), (b) or (c) and I have not modified
+            it.
+
+        (d) I understand and agree that this project and the contribution
+            are public and that a record of the contribution (including all
+            personal information I submit with it, including my sign-off) is
+            maintained indefinitely and may be redistributed consistent with
+            this project or the open source license(s) involved.
+
+then you just add a line saying::
+
+        Signed-off-by: Random J Developer <random@developer.example.org>
+
+using your real name (sorry, no pseudonyms or anonymous contributions.)
+
+Some people also put extra tags at the end.  They'll just be ignored for
+now, but you can do this to mark internal company procedures or just
+point out some special detail about the sign-off.