Revert "v4l2: setting device parameters early"

This reverts commit b1ad9312331759679a9c956233716a67ae681d89.

Fixes Ticket #3517

Conflicts:

	libavdevice/v4l2.c

Requested-by: Giorgio Vazzana <mywing81@gmail.com>
Merged-by: Michael Niedermayer <michaelni@gmx.at>