lttng: add v4l tracing support

Changes are merged from this commit;
https://github.com/fahadusman/meta-tracing/commit/
a94f23f5c50cd3055ae891cc7988d575a0c98665

JIRA: http://jira.alm.mentorg.com:8080/browse/SB-2549

Signed-off-by: Yasir-Khan <yasir_khan@mentor.com>
Merge pull request #13 from Yasir-Khan/v4l_tracing

lttng: add v4l tracing support