Update from_dlpack tests and documentation (#70543)
Summary:
Part of https://github.com/pytorch/pytorch/issues/58742
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70543
Reviewed By: soulitzer
Differential Revision: D34172475
Pulled By: mruberry
fbshipit-source-id: d498764b8651a8b7a19181b3421aeebf28a5db2b
(cherry picked from commit 05332f164c4317e46e1242fdae483204e0412ef3)
