arm64: dts: qcom: sm8550: Enable download mode register write

Enable download mode setting for sm8550 which can help collect
ramdump for this SoC.

Signed-off-by: Mukesh Ojha <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
[bjorn: Updated tcsr offset, per Mukesh correction]
Signed-off-by: Bjorn Andersson <[e-mail]>

arch/arm64/boot/dts/qcom/sm8550.dtsi

···
 	firmware {
 		scm: scm {
 			compatible = "qcom,scm-sm8550", "qcom,scm";
+			qcom,dload-mode = <&tcsr 0x19000>;
 			interconnects = <&aggre2_noc MASTER_CRYPTO 0 &mc_virt SLAVE_EBI1 0>;
 		};
 	};