Merge changes from topic "cot-dt2c" into integration

* changes:
  feat(arm): update documentation for cot-dt2c
  feat(arm): remove the bl2 static c file
  feat(arm): generate tbbr c file CoT dt2c
  feat(arm): makefile invoke CoT dt2c
  feat(auth): standalone CoT dt2c tool
  refactor(auth): separate bl1 and bl2 CoT
  refactor(st): align the NV counter naming
  refactor(fvp): align the NV counter naming