ASoC: dt-bindings: audio-graph-card2: add missing mic-det-gpios

The yaml has "hp-det-gpios" property, but Audio-Graph-Card2 can handle
"mic-det-gpios" too. Add it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/877c2kaxn4.wl-kuninori.morimoto.gx@renesas.com


Signed-off-by: Mark Brown <broonie@kernel.org>