net: tc: Using u8_t for queue and thread priority
net: tc: Using u8_t for queue and thread priority

As the priority currently fits u8_t then use it instead of int
for priority value for queue and thread.

Signed-off-by: Jukka Rissanen <f9f077d1da4c7aa947f9864fa5a28c3588f6a45d@linux.intel.com>

nashif/zephyr,mbolivar/zephyr,zephyriot/zephyr,kraj/zephyr,ldts/zephyr,punitvara/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyriot/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,explora26/zephyr,galak/zephyr,kraj/zephyr,Vudentz/zephyr,ldts/zephyr,explora26/zephyr,mbolivar/zephyr,zephyriot/zephyr,punitvara/zephyr,punitvara/zephyr,finikorg/zephyr,ldts/zephyr,zephyriot/zephyr,GiulianoFranchetto/zephyr,GiulianoFranchetto/zephyr,kraj/zephyr,ldts/zephyr,kraj/zephyr,kraj/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,explora26/zephyr,nashif/zephyr,mbolivar/zephyr,finikorg/zephyr,galak/zephyr,nashif/zephyr,zephyriot/zephyr,mbolivar/zephyr,nashif/zephyr,punitvara/zephyr,finikorg/zephyr,galak/zephyr,explora26/zephyr,Vudentz/zephyr,ldts/zephyr,Vudentz/zephyr,finikorg/zephyr,explora26/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,mbolivar/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,galak/zephyr