ARM: dts: qcom: align SPMI PMIC ADC node name with dtschema

Bindings expect VADC node name to be "adc":

pmic@0: 'vadc@3100' does not match any of the regexes

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Reviewed-by: David Heidelberg <[e-mail]>
Reviewed-by: Stephen Boyd <[e-mail]>
Reviewed-by: Vinod Koul <[e-mail]>
Signed-off-by: Bjorn Andersson <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/arm/boot/dts/qcom-pm8941.dtsi

···
 			#thermal-sensor-cells = <0>;
 		};
 
-		pm8941_vadc: vadc@3100 {
+		pm8941_vadc: adc@3100 {
 			compatible = "qcom,spmi-vadc";
 			reg = <0x3100>;
 			interrupts = <0x0 0x31 0x0 IRQ_TYPE_EDGE_RISING>;

arch/arm/boot/dts/qcom-pma8084.dtsi

···
 			io-channel-names = "thermal";
 		};
 
-		pma8084_vadc: vadc@3100 {
+		pma8084_vadc: adc@3100 {
 			compatible = "qcom,spmi-vadc";
 			reg = <0x3100>;
 			interrupts = <0x0 0x31 0x0 IRQ_TYPE_EDGE_RISING>;