David Hu authored Jun 20, 2024 and Rahul Singh committed Jun 25, 2024

Some external projects have bumped their versions or changed the
addresses of their documentation.
Update the URLs of the related links in Kronos docs.

- Update links to Critical App Monitoring latest documentation.
- Update the link to "scarthgap-dev" branch of Cassini in README.
- Switch TF-M documentation links to TF-M RTD. Also put notes to
  highlight that Kronos docs and code specify different versions
  of TF-M.
- Other minor link updates/fixes.

Signed-off-by: David Hu <david.hu2@arm.com>