ASoC: mediatek: mt8192: refactor for I2S8/I2S9 DAI links of headset

As part of the refactoring to allow the same machine driver to be used for
the rt1015(p) and rt5682(s) codecs on the MT8192 platform, parse the
rt5682(s) codec from the headset-codec property in the devicetree and wire
it to the I2S8 and I2S9 backends.

Signed-off-by: Jiaxin Yu <jiaxin.yu@mediatek.com>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220408060552.26607-4-jiaxin.yu@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>