dt-bindings: timer: Convert snps,archs-gfrc to DT schema

Convert the Synopsys ARC HS 64-bit Timer binding to DT schema format.
It's a straight-forward conversion.

Signed-off-by: Rob Herring (Arm) <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Daniel Lezcano <[e-mail]>

Documentation/devicetree/bindings/timer/snps,archs-gfrc.txt

···
-Synopsys ARC Free Running 64-bit Global Timer for ARC HS CPUs
-- clocksource provider for SMP SoC
-
-Required properties:
-
-- compatible : should be "snps,archs-gfrc"
-- clocks     : phandle to the source clock
-
-Example:
-
-	gfrc {
-		compatible = "snps,archs-gfrc";
-		clocks = <&core_clk>;
-	};

Documentation/devicetree/bindings/timer/snps,archs-gfrc.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/snps,archs-gfrc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Synopsys ARC Free Running 64-bit Global Timer for ARC HS CPUs
+
+maintainers:
+  - Vineet Gupta <[e-mail]>
+
+properties:
+  compatible:
+    const: snps,archs-gfrc
+
+  clocks:
+    maxItems: 1
+
+required:
+  - compatible
+  - clocks
+
+additionalProperties: false
+
+examples:
+  - |
+    timer {
+        compatible = "snps,archs-gfrc";
+        clocks = <&core_clk>;
+    };