dts: arm: st: u0: disable lptim2 by default

LPTIM2 is enabled by default; disable it to avoid
the build failure:
"Error: Only one LPTIM instance should be enabled"
when LPTIM1 is also enabled in the DTS.

Signed-off-by: Fabrice DJIATSA <fabrice.djiatsa-ext@st.com>

dts/arm/st/u0/stm32u0.dtsi

@@ -573,6 +573,7 @@
 			reg = <0x40009400 0x400>;
 			interrupts = <18 1>;
 			interrupt-names = "combined";
+			status = "disabled";
 		};
 
 		tsc: tsc@40024000 {