LaTeX adjustbox is known to cause pdf documentation build breakages
with some newer Sphinx versions. So, don't use it.

While here, adjust table sizes in order to better produce the
pdf output.

Fixes: c0da55b9 ("media: v4l2: Documentation for HEVC CIDs")
Cc: Smitha T Murthy <smitha.t@samsung.com>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>