ASoC: qcom: add generic bit masks for RDMA and WRDMA

This patch adds generic masks for accessing bits in rdma/wrdma
registers. Doing this would simplify the driver and adding capture
support would be much simpler. Also there is no point in having same
bit masks for bits in both rdma and wrdma registers.

This patch also deletes the RDMA specific bit masks and makes the code
use the generic bit masks.

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