ASoC: meson: gx-card: fix sound-dai dt schema

There is a fair amount of warnings when running 'make dtbs_check' with
amlogic,gx-sound-card.yaml.

Ex:
arch/arm64/boot/dts/amlogic/meson-gxm-q200.dt.yaml: sound: dai-link-0:sound-dai:0:1: missing phandle tag in 0
arch/arm64/boot/dts/amlogic/meson-gxm-q200.dt.yaml: sound: dai-link-0:sound-dai:0:2: missing phandle tag in 0
arch/arm64/boot/dts/amlogic/meson-gxm-q200.dt.yaml: sound: dai-link-0:sound-dai:0: [66, 0, 0] is too long

The reason is that the sound-dai phandle provided has cells, and in such
case the schema should use 'phandle-array' instead of 'phandle'.

Fixes: fd00366b

 ("ASoC: meson: gx: add sound card dt-binding documentation")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20210524093448.357140-1-jbrunet@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>