ASoC: codecs: lpass-tx-macro: set npl clock rate correctly

NPL clock rate is twice the MCLK rate, so set this correctly to
avoid soundwire timeouts.

Fixes: c39667dd

 ("ASoC: codecs: lpass-tx-macro: add support for lpass tx macro")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210331171235.24824-1-srinivas.kandagatla@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>