iio:adc:qcom-spmi-vadc: add default scale to LR_MUX2_BAT_ID channel

iio:adc:qcom-spmi-vadc: add default scale to LR_MUX2_BAT_ID channel

Checking at both msm8909-pm8916.dtsi and msm8916.dtsi from downstream
it is indicated that "batt_id" channel has to be scaled with the default
function:

	chan@31 {
		label = "batt_id";
		reg = <0x31>;
		qcom,decimation = <0>;
		qcom,pre-div-channel-scaling = <0>;
		qcom,calibration-type = "ratiometric";
		qcom,scale-function = <0>;
		qcom,hw-settle-time = <0xb>;
		qcom,fast-avg-setup = <0>;
	};

Change LR_MUX2_BAT_ID scaling accordingly.

Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Fixes: 7c271eea7b8a ("iio: adc: spmi-vadc: Changes to support different scaling")
Link: https://lore.kernel.org/r/20210113151808.4628-2-jonathan.albrieux@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>