ARM: dts: TS-4800: add FPGA's IRQ controller support

Enable FPGA's IRQ controller. It is in charge of dispatching interrupts
generated by IPs in the FPGA. The SoC is notified that an interrupt
occurred through a GPIO.
Signed-off-by: Damien Riegel <damien.riegel@savoirfairelinux.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx51-ts4800.dts

@@ -165,6 +165,17 @@ touchscreen {
 			reg = <0x12000 0x1000>;
 			syscon = <&syscon 0x10 6>;
 		};
+
+		fpga_irqc: fpga-irqc@15000 {
+			compatible = "technologic,ts4800-irqc";
+			reg = <0x15000 0x1000>;
+			pinctrl-names = "default";
+			pinctrl-0 = <&pinctrl_interrupt_fpga>;
+			interrupt-parent = <&gpio2>;
+			interrupts= <9 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-controller;
+			#interrupt-cells = <1>;
+		};
 	};
 };
 
@@ -228,6 +239,12 @@ MX51_PAD_KEY_COL5__I2C2_SDA		0x400001ed
 		>;
 	};
 
+	pinctrl_interrupt_fpga: fpgaicgrp {
+		fsl,pins = <
+			MX51_PAD_EIM_D27__GPIO2_9		0xe5
+		>;
+	};
+
 	pinctrl_lcd: lcdgrp {
 		fsl,pins = <
 			MX51_PAD_DISP1_DAT0__DISP1_DAT0		0x5