ARM: dts: stm32: leverage OP-TEE ASync notif on STM32MP13x Soc family

Enables use of GIC PPI#15 for OP-TEE asynchronous notifications
on stm32mp13 platforms.
Signed-off-by: Etienne Carriere <etienne.carriere@foss.st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

arch/arm/boot/dts/st/stm32mp131.dtsi

@@ -33,6 +33,8 @@ firmware {
 		optee {
 			method = "smc";
 			compatible = "linaro,optee-tz";
+			interrupt-parent = <&intc>;
+			interrupts = <GIC_PPI 15 (GIC_CPU_MASK_SIMPLE(1) | IRQ_TYPE_LEVEL_LOW)>;
 		};
 
 		scmi: scmi {