message: [openthread] enable OT_LINK_METRICS_SUBJECT for only Thread >= 1.2
diff: @@ -35,7 +35,9 @@ set(OT_COMMISSIONER ON CACHE BOOL "enable commissioner" FORCE)
  set(OT_DAEMON ON CACHE BOOL "enable daemon mode" FORCE)
  set(OT_JOINER ON CACHE BOOL "enable joiner" FORCE)
  set(OT_LEGACY ON CACHE STRING "enable legacy network support" FORCE)
  +if (NOT OT_THREAD_VERSION EQUAL "1.1")
  set(OT_LINK_METRICS_SUBJECT ON CACHE BOOL "enable link metrics subject" FORCE)
  +endif()
  set(OT_SLAAC ON CACHE BOOL "enable SLAAC" FORCE)
  set(OT_TREL ON CACHE BOOL "enable TREL")
  