iio: chemical: bme680: Remove field value defines

Remove BME680_RUN_GAS_EN_BIT and BME680_NB_CONV_0_VAL field value
definitions because the fields are simply boolean and integer
respectively.
Signed-off-by: David Frey <dpfrey@gmail.com>
Reviewed-by: Himanshu Jha <himanshujha199640@gmail.com>
Tested-by: Himanshu Jha <himanshujha199640@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/chemical/bme680.h

@@ -54,8 +54,6 @@
 #define BME680_REG_CTRL_GAS_1			0x71
 #define   BME680_RUN_GAS_MASK			BIT(4)
 #define   BME680_NB_CONV_MASK			GENMASK(3, 0)
-#define     BME680_RUN_GAS_EN_BIT		BIT(4)
-#define     BME680_NB_CONV_0_VAL		0
 
 #define BME680_REG_MEAS_STAT_0			0x1D
 #define   BME680_GAS_MEAS_BIT			BIT(6)

drivers/iio/chemical/bme680_core.c

@@ -572,10 +572,11 @@ static int bme680_gas_config(struct bme680_data *data)
 		return ret;
 	}
 
-	/* Selecting the runGas and NB conversion settings for the sensor */
+	/* Enable the gas sensor and select heater profile set-point 0 */
 	ret = regmap_update_bits(data->regmap, BME680_REG_CTRL_GAS_1,
 				 BME680_RUN_GAS_MASK | BME680_NB_CONV_MASK,
-				 BME680_RUN_GAS_EN_BIT | BME680_NB_CONV_0_VAL);
+				 FIELD_PREP(BME680_RUN_GAS_MASK, 1) |
+				 FIELD_PREP(BME680_NB_CONV_MASK, 0));
 	if (ret < 0)
 		dev_err(dev, "failed to write ctrl_gas_1 register\n");