V4L/DVB (8346): gspca: Bad pixel format of bridge VC0321.

vc032x:   Light frequency was not initialized.
          Change the pixel format of bridge VC0321 to V4L2_PIX_FMT_YUV420
              ('YU12').
          Set a bridge to all webcams.

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>