ARM: dts: exynos: correct PMIC interrupt trigger level on Spring

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: 53dd4138 ("ARM: dts: Add exynos5250-spring device tree")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20201210212903.216728-4-krzk@kernel.org

arch/arm/boot/dts/exynos5250-spring.dts

@@ -109,7 +109,7 @@ pmic@66 {
 		compatible = "samsung,s5m8767-pmic";
 		reg = <0x66>;
 		interrupt-parent = <&gpx3>;
-		interrupts = <2 IRQ_TYPE_NONE>;
+		interrupts = <2 IRQ_TYPE_LEVEL_LOW>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&s5m8767_irq &s5m8767_dvs &s5m8767_ds>;
 		wakeup-source;