arm64: dts: exynos: correct PMIC interrupt trigger level on TM2

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: 01e5d235 ("arm64: dts: exynos: Add dts file for Exynos5433-based TM2 board")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20201210212903.216728-7-krzk@kernel.org

arch/arm64/boot/dts/exynos/exynos5433-tm2-common.dtsi

@@ -388,7 +388,7 @@ &hsi2c_0 {
 	pmic@66 {
 		compatible = "samsung,s2mps13-pmic";
 		interrupt-parent = <&gpa0>;
-		interrupts = <7 IRQ_TYPE_NONE>;
+		interrupts = <7 IRQ_TYPE_LEVEL_LOW>;
 		reg = <0x66>;
 		samsung,s2mps11-wrstbi-ground;