arm64: dts: qcom: sc8180x: align APSS with bindings

SC8180x APSS Devicetree bindings expect qcom,sc8180x-apss-shared to use
qcom,sdm845-apss-shared fallback:

sc8180x-lenovo-flex-5g.dtb: mailbox@17c00000: compatible: 'oneOf' conditional failed, one must be fixed:
['qcom,sc8180x-apss-shared'] is too short

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Reviewed-by: Konrad Dybcio <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Bjorn Andersson <[e-mail]>

arch/arm64/boot/dts/qcom/sc8180x.dtsi

···
 		};
 
 		apss_shared: mailbox@17c00000 {
-			compatible = "qcom,sc8180x-apss-shared";
+			compatible = "qcom,sc8180x-apss-shared", "qcom,sdm845-apss-shared";
 			reg = <0x0 0x17c00000 0x0 0x1000>;
 			#mbox-cells = <1>;
 		};