include: added new sensor channel SENSOR_CHAN_GAS_RES
include: added new sensor channel SENSOR_CHAN_GAS_RES

Added new sensor channel SENSOR_CHAN_GAS_RES to support the bme680

Signed-off-by: Bosch Sensortec <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@bosch-sensortec.com>

zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,galak/zephyr,Vudentz/zephyr,Vudentz/zephyr,nashif/zephyr,GiulianoFranchetto/zephyr,nashif/zephyr,finikorg/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,galak/zephyr,nashif/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,Vudentz/zephyr,Vudentz/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr