Merge changes from topic "bk/smccc_feature"

* changes:
  fix(brbe): report BRBE support with later revisions
  test(SMCCC): test SMCCC_ARCH_FEATURE_AVAILABILITY
  refactor(SMCCC): use a macro to check for the SMCCC version
  feat: add register definitions needed for SMCCC_ARCH_FEATURE_AVAILABILITY