dts: arm: st: wba: do not enable standby pm mode

Do not enable Standby low-power mode by default since the associated
Kconfig PM_S2RAM is disabled by default. Otherwise we could enter an
unsupported low-power state.

Signed-off-by: Guillaume Gautier <guillaume.gautier-ext@st.com>
(cherry picked from commit f1bfbb06277cca9d8576f6aac99e7777f7c0ab22)
diff --git a/dts/arm/st/wba/stm32wba.dtsi b/dts/arm/st/wba/stm32wba.dtsi
index 4ae4549..0039b15 100644
--- a/dts/arm/st/wba/stm32wba.dtsi
+++ b/dts/arm/st/wba/stm32wba.dtsi
@@ -33,7 +33,8 @@
 			device_type = "cpu";
 			compatible = "arm,cortex-m33";
 			reg = <0>;
-			cpu-power-states = <&stop0 &stop1 &standby>;
+			/* Do not add &standby here since CONFIG_PM_S2RAM is disabled by default */
+			cpu-power-states = <&stop0 &stop1>;
 			#address-cells = <1>;
 			#size-cells = <1>;