tc22.4: remove Debian Swr/Hwr rendering support mentions

Changes include:
  - remove all Debian Swr/Hwr rendering support mentions;
  - minor updates to the TC boot flow diagram;
  - add required commands for MTE sanity test;
  - add PAUTH known inconsistent failing tests known issue;
  - add new "Troubleshooting: common problems and solutions" section.

Signed-off-by: Sergio Alves <sergio.dasilvalves@arm.com>