dt-bindings: display: mediatek, mutex: Fix mediatek, gce-events type

The mediatek,gce-events property needs as value an array of uint32
corresponding to the CMDQ events to listen to, and not any phandle.

Fixes: 4ed545e7

 ("dt-bindings: display: mediatek: disp: split each block to individual yaml")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: jason-jh.lin <jason-jh.lin@mediatek.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220309134702.9942-3-jason-jh.lin@mediatek.com