ASoC: ad193x: Remove non-functional DAPM route controls

DAPM route controls only take effect on paths where the sink is a mixer or a
mux, furthermore the control must be a control assigned to the mixer or mux.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>