ARM: dts: stm32: add exti entry 69 for HDMI-CEC on stm32mp151

Add exti entry 69 used for HDMI-CEC wake up.
This event is mapped to GIC 94.

It is used by node m4_cec: cec@40016000 in
arch/arm/boot/dts/stm32mp15-m4-srm.dtsi

Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com>
Change-Id: I47a71799d779b6f57ca227aed6009abbc08ef11d
Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/linux-stm32/+/274972
Reviewed-by: Antonio Maria BORNEO <antonio.borneo@st.com>
Reviewed-by: Amelie DELAUNAY <amelie.delaunay@foss.st.com>
Tested-by: Antonio Maria BORNEO <antonio.borneo@st.com>
Domain-Review: Amelie DELAUNAY <amelie.delaunay@foss.st.com>

arch/arm/boot/dts/stm32mp151.dtsi

@@ -1259,6 +1259,7 @@
 					<61 0 &intc GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>,
 					<65 0 &intc GIC_SPI 144 IRQ_TYPE_LEVEL_HIGH>,
 					<68 0 &intc GIC_SPI 143 IRQ_TYPE_LEVEL_HIGH>,
+					<69 0 &intc GIC_SPI 94  IRQ_TYPE_LEVEL_HIGH>,
 					<70 0 &intc GIC_SPI 62  IRQ_TYPE_LEVEL_HIGH>,
 					<73 0 &intc GIC_SPI 129 IRQ_TYPE_LEVEL_HIGH>;
 			};