[media] cec-ioc-dqevent.rst: fix some undefined references

[media] cec-ioc-dqevent.rst: fix some undefined references

Documentation/output/cec.h.rst:6: WARNING: c:type reference target not found: cec_event_state_change
Documentation/output/cec.h.rst:6: WARNING: c:type reference target not found: cec_event_state_change
Documentation/output/cec.h.rst:6: WARNING: c:type reference target not found: cec_event_lost_msgs
Documentation/output/cec.h.rst:6: WARNING: c:type reference target not found: cec_event_lost_msgs
Documentation/output/cec.h.rst:6: WARNING: c:type reference target not found: cec_event_state_change
Documentation/output/cec.h.rst:6: WARNING: c:type reference target not found: cec_event_lost_msgs

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>