Renamed various msp3400 routing defines to be more consistent and less
confusing. Esp. the MSP_DSP_OUT defines were confusing since it is really
a DSP input.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

- implement VIDIOC_INT_S_AUDIO_ROUTING for msp3400 and tvaudio
- use the new command in bttv, pvrusb2 and em28xx.
- remove the now obsolete MSP_SET_MATRIX from msp3400 (yeah!)
- remove the obsolete VIDIOC_S_AUDIO from msp3400.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Moved msp3400.h to msp3400-driver.h.
Created media/msp3400.h with the new routing defines and lots of comments.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>