arm64: dts: exynos: correct PMIC interrupt trigger level on Espresso

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: 9589f772 ("arm64: dts: Add S2MPS15 PMIC node on exynos7-espresso")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20201210212903.216728-8-krzk@kernel.org

arch/arm64/boot/dts/exynos/exynos7-espresso.dts

@@ -90,7 +90,7 @@ &hsi2c_4 {
 	pmic@66 {
 		compatible = "samsung,s2mps15-pmic";
 		reg = <0x66>;
-		interrupts = <2 IRQ_TYPE_NONE>;
+		interrupts = <2 IRQ_TYPE_LEVEL_LOW>;
 		interrupt-parent = <&gpa0>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&pmic_irq>;