Fix smatch warning in mxc_jpeg_queue_setup, check *nplanes against
current format:

drivers/media/platform/imx-jpeg/mxc-jpeg.c:1070
mxc_jpeg_queue_setup()
         warn: potential user controlled iterator 'i' (array size 2 vs 7)
Signed-off-by: Mirela Rabulea <mirela.rabulea@oss.nxp.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>