ARM: mvebu: Add support for NOR flash device on Openblocks AX3 board

The Plat'home Openblocks AX3 has a 128 MiB NOR flash device connected
to the Device Bus. This commit adds the device tree node to support this device.

The SoC supports a flexible and dynamic decoding window allocation scheme;
but since this feature is still not implemented we need to specify the window
base address in the device tree node itself.
This base address has been selected in a completely arbitrary fashion.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

arch/arm/boot/dts/armada-xp-openblocks-ax3-4.dts

@@ -139,5 +139,34 @@ usb@d0050000 {
 		usb@d0051000 {
 			status = "okay";
 		};
+
+		devbus-bootcs@d0010400 {
+			status = "okay";
+			ranges = <0 0xf0000000 0x8000000>; /* @addr 0xf000000, size 0x8000000 */
+
+			/* Device Bus parameters are required */
+
+			/* Read parameters */
+			devbus,bus-width    = <8>;
+			devbus,turn-off-ps  = <60000>;
+			devbus,badr-skew-ps = <0>;
+			devbus,acc-first-ps = <124000>;
+			devbus,acc-next-ps  = <248000>;
+			devbus,rd-setup-ps  = <0>;
+			devbus,rd-hold-ps   = <0>;
+
+			/* Write parameters */
+			devbus,sync-enable = <0>;
+			devbus,wr-high-ps  = <60000>;
+			devbus,wr-low-ps   = <60000>;
+			devbus,ale-wr-ps   = <60000>;
+
+			/* NOR 128 MiB */
+			nor@0 {
+				compatible = "cfi-flash";
+				reg = <0 0x8000000>;
+				bank-width = <2>;
+			};
+		};
 	};
 };