ARM: dts: armada-38x: Fix irq type for pca955

[ Upstream commit 8d451417 ]

As written in the datasheet the PCA955 can only handle low level irq and
not edge irq.

Without this fix the interrupt is not usable for pca955: the gpio-pca953x
driver already set the irq type as low level which is incompatible with
edge type, then the kernel prevents using the interrupt:

"irq: type mismatch, failed to map hwirq-18 for
/soc/internal-regs/gpio@18100!"

Fixes: 928413bd ("ARM: mvebu: Add Armada 388 General Purpose
Development Board support")
Cc: stable@vger.kernel.org
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>

arch/arm/boot/dts/armada-388-gp.dts

@@ -91,7 +91,7 @@ expander0: pca9555@20 {
 					pinctrl-names = "default";
 					pinctrl-0 = <&pca0_pins>;
 					interrupt-parent = <&gpio0>;
-					interrupts = <18 IRQ_TYPE_EDGE_FALLING>;
+					interrupts = <18 IRQ_TYPE_LEVEL_LOW>;
 					gpio-controller;
 					#gpio-cells = <2>;
 					interrupt-controller;
@@ -103,7 +103,7 @@ expander1: pca9555@21 {
 					compatible = "nxp,pca9555";
 					pinctrl-names = "default";
 					interrupt-parent = <&gpio0>;
-					interrupts = <18 IRQ_TYPE_EDGE_FALLING>;
+					interrupts = <18 IRQ_TYPE_LEVEL_LOW>;
 					gpio-controller;
 					#gpio-cells = <2>;
 					interrupt-controller;