media: pulse8-cec: add 2nd debug level

Use debug level 2 to show the low-level Pulse-Eight commands.

Also show the message to transmit on debug level 1 and add a
debug log to show where the transmit failed.

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