ASoC: mt8173: remove unnecessary micbias widget in route

The micbias1/2 are connected to route as SUPPLY usage. It was not
take effect since they were MICBIAS type. To keep the same register
settings, we have to remove it once the micbias1/2 widget is converted
to SUPPLY type.

Signed-off-by: Bard Liao <bardliao@realtek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>