Set default colorspace to SRGB for JPEG encoder and decoder devices,
to fix the following v4l2-compliance test failure:

	test VIDIOC_TRY_FMT: OK
		fail: v4l2-test-formats.cpp(818): fmt_raw.g_colorspace() != V4L2_COLORSPACE_SRGB

Also explicitly set transfer function, YCbCr encoding and quantization
range, as required by v4l2-compliance for the JPEG encoded side.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>