media: omap3isp: use V4L2_COLORSPACE_SRGB instead of _JPEG

media: omap3isp: use V4L2_COLORSPACE_SRGB instead of _JPEG

JPEG colorspace should generally not be used unless it is actually
dealing with JPG data. This fixes v4l2-compliance errors:

	fail: v4l2-test-formats.cpp(416): pixelformat != V4L2_PIX_FMT_JPEG && pixelformat != V4L2_PIX_FMT_MJPEG && colorspace == V4L2_COLORSPACE_JPEG
	fail: v4l2-test-formats.cpp(521): testColorspace(!node->is_io_mc, pix.pixelformat, pix.colorspace, pix.ycbcr_enc, pix.quantization)
test VIDIOC_TRY_FMT: FAIL

Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>