uart_qmsi: fix possible divide-by-zero
uart_qmsi: fix possible divide-by-zero

The line control value could result in a baud divisor of zero.
Check this condition and return -EINVAL if that is the case.

Signed-off-by: Andrew Boie <aab045b28152628be6af0e556050d0381fd0a34d@intel.com>

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