media: v4l2-jpeg: Remove unused v4l2_jpeg_parse_* wrappers

The functions:
  v4l2_jpeg_parse_huffman_tables()
  v4l2_jpeg_parse_quantization_tables()
  v4l2_jpeg_parse_scan_header()
and
  v4l2_jpeg_parse_frame_header()

were added in 2020 by
commit 50733b5b ("media: add v4l2 JPEG helpers")

but have remained unused.

Remove them.

They're all just wrappers around an underlying set of helpers,
which are all still called via v4l2_jpeg_parse_header().

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>