dt-bindings: riscv: Add Anlogic DR1V90

Add Anlogic DR1V90 FPSoC, featuring a UX900 RISC-V core as the
processing system (PS) and 94,464 LUTs programmable logic (PL). It is
used by the Milianke MLKPAI-FS01 board, a SBC equipped with 512MB DDR3
memory, USB-C UART, 1GbE RJ45 Ethernet, USB-A 2.0 port, TF card slot,
and 256Mbit Quad-SPI flash.

Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Junhui Liu <[e-mail]>
Signed-off-by: Conor Dooley <[e-mail]>

Documentation/devicetree/bindings/riscv/anlogic.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/riscv/anlogic.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Anlogic SoC-based boards
+
+maintainers:
+  - Junhui Liu <[e-mail]>
+
+description:
+  Anlogic SoC-based boards
+
+properties:
+  $nodename:
+    const: '/'
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - milianke,mlkpai-fs01
+          - const: anlogic,dr1v90
+
+additionalProperties: true
+
+...