MLK-22507: mxc-jpeg: Return rgb24 pixfmt from decoder when app14 is present

MLK-22507: mxc-jpeg: Return rgb24 pixfmt from decoder when app14 is present

When GST receives V4L2_EVENT_SOURCE_CHANGE, it calls g_fmt ioctl and
expects that the driver will report the pixel format.
So far, the driver was unable to distinguish, by looking at the jpeg
SOF marker, if an image is YUV444 or RGB24, both have 3 color components
and no subsampling.
Consider the colorspace is RGB if the transform flag from APP14 marker
segment has the value 0, in mxc_jpeg_parse, if needed, update the pixel
format from yuv444 to rgb24.

Signed-off-by: Mirela Rabulea <mirela.rabulea@nxp.com>
Reviewed-by: Robert Chiras <robert.chiras@nxp.com>