media: amphion: don't change the colorspace reported by decoder.

decoder will report the colorspace information
which is parsed from the sequence header,
if they are unspecified, just let application to determine it,
don't change it in driver.

Fixes: 6de8d628 ("media: amphion: add v4l2 m2m vpu decoder stateful driver")
Signed-off-by: Ming Qian <ming.qian@nxp.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>