devcietree: bindings: add some MFD Keymile FPGAs

These are the bindings for 2 MFD devices used on some of the Keymile boards.
The first one is the chassis managmenet bfticu FPGA.
The second one is the board controller (reset, LEDs, GPIOs) QRIO CPDL.
These FPGAs are used in the kmcoge4 board.

Signed-off-by: Valentin Longchamp <[e-mail]>
Signed-off-by: Scott Wood <[e-mail]>

Documentation/devicetree/bindings/mfd/bfticu.txt

···
+KEYMILE bfticu Chassis Management FPGA
+
+The bfticu is a multifunction device that manages the whole chassis.
+Its main functionality is to collect IRQs from the whole chassis and signals
+them to a single controller.
+
+Required properties:
+- compatible: "keymile,bfticu"
+- interrupt-controller: the bfticu FPGA is an interrupt controller
+- interrupts: the main IRQ line to signal the collected IRQs
+- #interrupt-cells : is 2 and their usage is compliant to the 2 cells variant
+  of Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+- interrupt-parent: the parent IRQ ctrl the main IRQ is connected to
+- reg: access on the parent local bus (chip select, offset in chip select, size)
+
+Example:
+
+	chassis-mgmt@3,0 {
+		compatible = "keymile,bfticu";
+		interrupt-controller;
+		#interrupt-cells = <2>;
+		reg = <3 0 0x100>;
+		interrupt-parent = <&mpic>;
+		interrupts = <6 1 0 0>;
+	};

Documentation/devicetree/bindings/mfd/qriox.txt

···
+KEYMILE qrio Board Control CPLD
+
+The qrio is a multifunction device that controls the KEYMILE boards based on
+the kmp204x design.
+It is consists of a reset controller, watchdog timer, LEDs, and 2 IRQ capable
+GPIO blocks.
+
+Required properties:
+- compatible: "keymile,qriox"
+- reg: access on the parent local bus (chip select, offset in chip select, size)
+
+Example:
+
+	board-control@1,0 {
+		compatible = "keymile,qriox";
+		reg = <1 0 0x80>;
+	};