Merge changes from topic "TrcDbgExt" into integration

* changes:
  feat(plat/fvp): enable trace extension features by default
  feat(trf): enable trace filter control register access from lower NS EL
  feat(trf): initialize trap settings of trace filter control registers access
  feat(sys_reg_trace): enable trace system registers access from lower NS ELs
  feat(sys_reg_trace): initialize trap settings of trace system registers access
  feat(trbe): enable access to trace buffer control registers from lower NS EL
  feat(trbe): initialize trap settings of trace buffer control registers access