media: cec: report Vendor ID after initialization

The CEC specification requires that the Vendor ID (if any) is reported
after a logical address was claimed.

This was never done, so add support for this.

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