dt-bindings: dma: mv-xor-v2: Convert to dtschema

Convert txt bindings of Marvell XOR v2 engines to dtschema to allow
for validation.

Also add missing property `dma-coherent` as `drivers/dma/mv_xor_v2.c`
calls various dma-coherent memory functions.

Signed-off-by: Shresth Prasad <[e-mail]>
Reviewed-by: Rob Herring (Arm) <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

Documentation/devicetree/bindings/dma/marvell,xor-v2.yaml

···
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/dma/marvell,xor-v2.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Marvell XOR v2 engines
+
+maintainers:
+  - Andrew Lunn <[e-mail]>
+
+properties:
+  compatible:
+    oneOf:
+      - const: marvell,xor-v2
+      - items:
+          - enum:
+              - marvell,armada-7k-xor
+          - const: marvell,xor-v2
+
+  reg:
+    items:
+      - description: DMA registers
+      - description: global registers
+
+  clocks:
+    minItems: 1
+    maxItems: 2
+
+  clock-names:
+    minItems: 1
+    items:
+      - const: core
+      - const: reg
+
+  msi-parent:
+    description:
+      Phandle to the MSI-capable interrupt controller used for
+      interrupts.
+    maxItems: 1
+
+  dma-coherent: true
+
+required:
+  - compatible
+  - reg
+  - msi-parent
+  - dma-coherent
+
+additionalProperties: false
+
+examples:
+  - |
+    xor0@6a0000 {
+        compatible = "marvell,armada-7k-xor", "marvell,xor-v2";
+        reg = <0x6a0000 0x1000>, <0x6b0000 0x1000>;
+        clocks = <&ap_clk 0>, <&ap_clk 1>;
+        clock-names = "core", "reg";
+        msi-parent = <&gic_v2m0>;
+        dma-coherent;
+    };

Documentation/devicetree/bindings/dma/mv-xor-v2.txt

···
-* Marvell XOR v2 engines
-
-Required properties:
-- compatible: one of the following values:
-    "marvell,armada-7k-xor"
-    "marvell,xor-v2"
-- reg: Should contain registers location and length (two sets)
-    the first set is the DMA registers
-    the second set is the global registers
-- msi-parent: Phandle to the MSI-capable interrupt controller used for
-  interrupts.
-
-Optional properties:
-- clocks: Optional reference to the clocks used by the XOR engine.
-- clock-names: mandatory if there is a second clock, in this case the
-   name must be "core" for the first clock and "reg" for the second
-   one
-
-
-Example:
-
-	xor0@400000 {
-		compatible = "marvell,xor-v2";
-		reg = <0x400000 0x1000>,
-		      <0x410000 0x1000>;
-		msi-parent = <&gic_v2m0>;
-		dma-coherent;
-	};