Add support for AMS CCS811 Digital Gas Sensor for monitoring
indoor air quality. This sensor reports the following parameters:
1. Co2 concentration
2. VOC concentration
3. Sensor voltage
4. Sensor current
This driver only supports polling mode as of now.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Manivannan Sadhasivam