[media] v4l: Fix documentation of V4L2_PIX_FMT_H264_MVC and VP8 pixel formats

The 'Code' column in the documentation should provide the real fourcc
code that is used. Changed the documentation to provide the fourcc
defined in videodev2.h

Signed-off-by: Kamil Debski <k.debski@samsung.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>