arm64: dts: mediatek: mt8192: Add missing gce-client-reg to mutex

Add the missing mediatek,gce-client-reg property to the mutex node to
allow it to use the GCE. This prevents the "can't parse gce-client-reg
property" error from being printed and should result in better
performance.

Fixes: b4b75bac ("arm64: dts: mt8192: Add display nodes")
Suggested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20240229-gce-client-reg-add-missing-mt8192-95-v1-1-b12c233a8a33@collabora.comSigned-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

arch/arm64/boot/dts/mediatek/mt8192.dtsi

@@ -1464,6 +1464,7 @@ mutex: mutex@14001000 {
 			reg = <0 0x14001000 0 0x1000>;
 			interrupts = <GIC_SPI 252 IRQ_TYPE_LEVEL_HIGH 0>;
 			clocks = <&mmsys CLK_MM_DISP_MUTEX0>;
+			mediatek,gce-client-reg = <&gce SUBSYS_1400XXXX 0x1000 0x1000>;
 			mediatek,gce-events = <CMDQ_EVENT_DISP_STREAM_DONE_ENG_EVENT_0>,
 					      <CMDQ_EVENT_DISP_STREAM_DONE_ENG_EVENT_1>;
 			power-domains = <&spm MT8192_POWER_DOMAIN_DISP>;