tests: workq: add support for null name parameter
tests: workq: add support for null name parameter

Validate k_work_queue_start() API with null name config, this should
not affect the name of queue's thread.

Signed-off-by: Lixin Guo <8de84fecf2daa12e9dd27dd0d7f47ee7775a73c0@intel.com>

galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr