message: [openthread] fix build for Thread 1.1
  This commit fixes the build for Thread 1.1 (when
  `OT_THREAD_VERSION=1.1` is passed) by enabling
  `OPENTHREAD_CONFIG_TMF_PROXY` for Thread >= 1.2.
diff: @@ -94,6 +94,11 @@ target_compile_definitions(ot-config INTERFACE
  "-DOPENTHREAD_CONFIG_MAX_STATECHANGE_HANDLERS=3"
  "-DOPENTHREAD_CONFIG_MLE_STEERING_DATA_SET_OOB_ENABLE=1"
  "-DOPENTHREAD_CONFIG_TCP_ENABLE=0"
  +)
  +
  +if (NOT OT_THREAD_VERSION STREQUAL "1.1")
  + target_compile_definitions(ot-config INTERFACE
  "-DOPENTHREAD_CONFIG_TMF_PROXY_DUA_ENABLE=1"
  "-DOPENTHREAD_CONFIG_TMF_PROXY_MLR_ENABLE=1"
  )
  +endif()
  