V4L/DVB: Cleanups for mt2060-integration

- some coding style fixes for newly added mt2060
- moved agc-config from fixed values in dib3000mc to configurable ones
- whitespace clean-ups for usb-id-file

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>