V4L/DVB (4932): Usbvision_v4l2: fix norm setting problems

Patch contents:
- fix i2c command broadcast (caused problems for SECAM norm setting)
- default input selection at driver open

Signed-off-by: Thierry MERLE <thierry.merle@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>