samples: boards: csk6: set platform allot list for exmcu sample

2 job 于develop/v3.4-zephyr-branch in 3 minute 和 22 second (queued for 1 second)
状态 作业 ID 名称 覆盖率
  Ztest
已通过 #41040
zgsz-02 generic
ztest_build_only

00:02:33

已通过 #41041
zgsz-03 with-device
ztest_device_test

00:03:22