ARM: dts: exynos: correct PMIC interrupt trigger level on Artik 5

The Samsung PMIC datasheets describe the interrupt line as active low
with a requirement of acknowledge from the CPU. Without specifying the
interrupt type in Devicetree, kernel might apply some fixed
configuration, not necessarily working for this hardware.

Fixes: b004a34bd0ff ("ARM: dts: exynos: Add exynos3250-artik5 dtsi file for ARTIK5 module")
Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Tested-by: Marek Szyprowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/arm/boot/dts/exynos3250-artik5.dtsi

···
 	pmic@66 {
 		compatible = "samsung,s2mps14-pmic";
 		interrupt-parent = <&gpx3>;
-		interrupts = <5 IRQ_TYPE_NONE>;
+		interrupts = <5 IRQ_TYPE_LEVEL_LOW>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&s2mps14_irq>;
 		reg = <0x66>;