V4L/DVB (3345): Fixes some bad global variables


- Debug global var is already used inside kernel.
- v4l_dbg now expects the debug var
- global vars inside msp34xx renamed to msp_*
Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>