media: v4l: Add packed YUV444 24bpp pixel format

The added format is V4L2_PIX_FMT_YUV24, this is a packed
YUV 4:4:4 format, with 8 bits for each component, 24 bits
per sample.

This format is used by the i.MX 8QuadMax and i.MX 8DualXPlus/8QuadXPlus
JPEG encoder/decoder.

Signed-off-by: Mirela Rabulea <mirela.rabulea@nxp.com>
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>