* add custom_cpu testcase

* update test_custom_device_setup

* update path to custom_runtime

* fix cmd wait

* test Linux only

* setup once

* integrate to one run_cmd

* add pip install

* change timeout

* add debug string

* add debug string

* add debug string

* use os.system and change module name

* add runtime

* add more debug message

* continue debug

* timestamp

* fix testcase import bug

* remove error message

* set TIMEOUT property

* add xpu backward testcase

* polish code

* fix self.custom_op error

* support custom_xpu

* update cmake to test xpu

* support custom_xpu, verify mechanism

* fix test_custom_relu_op_xpu_setup.py, test=kunlun

* fix FLAGS_init_allocated_mem

* cancel TIMEOUT property

* reset FLAGS_init_allocated_mem property