arm64: dts: mediatek: mt6359: fix dtbs_check error for audio-codec

arm64: dts: mediatek: mt6359: fix dtbs_check error for audio-codec

This change fixes these dtbs_check errors for audio-codec:
1. pmic: 'mt6359codec' does not match any of the regexes: 'pinctrl-[0-9]+'
 - Replace device node name to generic 'audio-codec'
2. pmic: regulators: 'compatible' is a required property
 - Add 'mediatek,mt6359-codec' to compatible.

Fixes: 3b7d143be4b7 ("arm64: dts: mt6359: add PMIC MT6359 related nodes")
Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20250217113736.1867808-1-macpaul.lin@mediatek.com
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>