media: cec-funcs.h: use new CEC_OP_UI_CMD defines

When the new CEC_OP_UI_CMD defines were added I forgot to update this
header to use these new defines. This is now fixed.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>