media: vim2m: use v4l2_m2m_buf_copy_data

Use the new v4l2_m2m_buf_copy_data() function in vim2m.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>