ARM: dts: imx6qdl-phytec-pfla02: Use IRQ_TYPE specifier

Replace magic number with the proper IRQ_TYPE specifier to improve DT
readability.
Signed-off-by: NHernán Gonzalez <hernan@vanguardiasur.com.ar>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6qdl-phytec-pfla02.dtsi

@@ -115,7 +115,7 @@
 		compatible = "dlg,da9063";
 		reg = <0x58>;
 		interrupt-parent = <&gpio2>;
-		interrupts = <9 0x8>; /* active-low GPIO2_9 */
+		interrupts = <9 IRQ_TYPE_LEVEL_LOW>; /* active-low GPIO2_9 */
 
 		regulators {
 			vddcore_reg: bcore1 {