powerpc/amigaone: Limit ISA I/O range to 4k in the device tree

The kernel reserves the I/O address space from 0x0 to 0xfff for legacy
ISA devices. Change the ranges property for the PCI2ISA bridge to match
the kernels behavior, even if the ranges property isn't used for now.
Signed-off-by: Gerhard Pircher <gerhard_pircher@gmx.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/boot/dts/amigaone.dts

@@ -70,8 +70,8 @@
 			devsel-speed = <0x00000001>;
 			min-grant = <0>;
 			max-latency = <0>;
-			/* First 64k for I/O at 0x0 on PCI mapped to 0x0 on ISA. */
-			ranges = <0x00000001 0 0x01000000 0 0x00000000 0x00010000>;
+			/* First 4k for I/O at 0x0 on PCI mapped to 0x0 on ISA. */
+			ranges = <0x00000001 0 0x01000000 0 0x00000000 0x00001000>;
 			interrupt-parent = <&i8259>;
 			#interrupt-cells = <2>;
 			#address-cells = <2>;