Merge changes from topics "plat_tests_scalability", "sb/tc-plat-tests" into integration

* changes:
  test(tc): unify platform tests traces
  test(tc): return test failures count for tfm-testsuite
  test(tc): move platform tests in their own function
  test(tc): centralize platform error handling
  refactor(tc): define PLATFORM_TESTS for scale

diff --cc plat/arm/board/tc/platform.mk
Simple merge

diff --cc plat/arm/board/tc/tc_bl31_setup.c
Simple merge