ASoC: da7219: Fix Sidetone to work regardless of DAI capture

Previously Sidetone would operate only when capture to DAI was in
progress, due to DAPM path configuration. There is no reason why
this should not operate without DAI capture, so this patch updates
the DAPM path accordingly.

Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Mark Brown <broonie@kernel.org>