ARM: dts: DRA7: fix interrupt-cells for GPIO

GPIO modules are also interrupt sources. However, they require both the
GPIO number and IRQ type to function properly.

By declaring that GPIO uses interrupt-cells=<1>, we essentially do not
allow users of the nodes to use the interrupt property appropritely.

With this change, the following now works:

interrupt-parent = <&gpio6>;
interrupts = <5 IRQ_TYPE_LEVEL_LOW>;

Fixes: 6e58b8f1daaf ('ARM: dts: DRA7: Add the dts files for dra7 SoC and dra7-evm board')
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/dra7.dtsi

@@ -245,7 +245,7 @@
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 		};
 
 		gpio2: gpio@48055000 {
@@ -256,7 +256,7 @@
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 		};
 
 		gpio3: gpio@48057000 {
@@ -267,7 +267,7 @@
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 		};
 
 		gpio4: gpio@48059000 {
@@ -278,7 +278,7 @@
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 		};
 
 		gpio5: gpio@4805b000 {
@@ -289,7 +289,7 @@
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 		};
 
 		gpio6: gpio@4805d000 {
@@ -300,7 +300,7 @@
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 		};
 
 		gpio7: gpio@48051000 {
@@ -311,7 +311,7 @@
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 		};
 
 		gpio8: gpio@48053000 {
@@ -322,7 +322,7 @@
 			gpio-controller;
 			#gpio-cells = <2>;
 			interrupt-controller;
-			#interrupt-cells = <1>;
+			#interrupt-cells = <2>;
 		};
 
 		uart1: serial@4806a000 {