V4L/DVB (3261): msp3400.c cleanup (almost all cosmetic)

- Step 1 of the msp3400.c cleanup.
Most changes are all cosmetic (moved code around, renamed functions
and variables).
New additions:
- VIDIOC_LOG_STATUS for debugging.
- More user friendly messages on driver load.
- 'simple' renamed to 'autodetect'
- 'simpler' renamed to 'autoselect'

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br>