arm64: dts: qcom: msm8998: Add missing power domain to MMSS SMMU

The MMSS SMMU has its own power domain. Attach it so that we can drop
the "keep it always-on" hack.

Fixes: 05ce21b5 ("arm64: dts: qcom: msm8998: Configure the multimedia subsystem iommu")
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230531-topic-8998_mmssclk-v3-2-ba1b1fd9ee75@linaro.orgSigned-off-by: Bjorn Andersson <andersson@kernel.org>

arch/arm64/boot/dts/qcom/msm8998.dtsi

@@ -2772,6 +2772,8 @@ mmss_smmu: iommu@cd00000 {
 				<GIC_SPI 261 IRQ_TYPE_LEVEL_HIGH>,
 				<GIC_SPI 262 IRQ_TYPE_LEVEL_HIGH>,
 				<GIC_SPI 272 IRQ_TYPE_LEVEL_HIGH>;
+
+			power-domains = <&mmcc BIMC_SMMU_GDSC>;
 		};
 
 		remoteproc_adsp: remoteproc@17300000 {