ASoC: q6afe: dt-bindings: Update input range for qcom,sd-lines

Input to qcom,sd-lines should be between 0 and 3 instead of
1 to 4 as 0 corresponds to BIT(0) which is MI2S_SD0 line.
Bit 1 to 3 corresponds to SD1 to SD3 lines respectively.
Updated documentation for the same.

Signed-off-by: Rohit kumar <rohitkr@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>