ASoC: qcom: remove hardcoded dma channel

This patch removes hardcoded dma channel value in lpass driver, Now the
dma channel allocation happens in the SOC specific layer. This will
allow different LPASS integrations to use the lpass driver in more
generic way.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Tested-by: Kenneth Westfield <kwestfie@codeaurora.org>
Acked-by: Kenneth Westfield <kwestfie@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>