ASoC: qcom: add wrdma register details to lpass_variant

This patch adds wrdma related register offsets, wrdma channel start
and shifts into lpass variant structure.

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