arm64: dts: qcom: qcs615: Add IMEM and PIL info region

Add a simple-mfd representing IMEM on QCS615 and define the PIL
relocation info region as its child. The PIL region in IMEM is used to
communicate load addresses of remoteproc to post mortem debug tools, so
that these tools can collect ramdumps.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Lijuan Gao <quic_lijuang@quicinc.com>
Link: https://lore.kernel.org/r/20250526-add_qcs615_remoteproc_support-v4-4-06a7d8bed0b5@quicinc.com

Author: lijuangg

arch/arm64/boot/dts/qcom/qcs615.dtsi

@@ -3323,6 +3323,20 @@
 			reg = <0x0 0x0c3f0000 0x0 0x400>;
 		};
 
+		sram@14680000 {
+			compatible = "qcom,qcs615-imem", "syscon", "simple-mfd";
+			reg = <0x0 0x14680000 0x0 0x2c000>;
+			ranges = <0 0 0x14680000 0x2c000>;
+
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			pil-reloc@2a94c {
+				compatible = "qcom,pil-reloc-info";
+				reg = <0x2a94c 0xc8>;
+			};
+		};
+
 		apps_smmu: iommu@15000000 {
 			compatible = "qcom,qcs615-smmu-500", "qcom,smmu-500", "arm,mmu-500";
 			reg = <0x0 0x15000000 0x0 0x80000>;