drivers: grove/temperature: ADC resolution to be 12-bit
drivers: grove/temperature: ADC resolution to be 12-bit

The driver itself expects the ADC resolution to be 12-bit.
So set it.

Signed-off-by: Daniel Leung <d94e04d205b5962d7873a139ef298b03c1717f72@intel.com>

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