dt-bindings: Add bindings for peci-aspeed

Add device tree bindings for the peci-aspeed controller driver.
Co-developed-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
Link: https://lore.kernel.org/r/20220208153639.255278-3-iwona.winiarska@intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/peci/peci-aspeed.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/peci/peci-aspeed.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Aspeed PECI Bus Device Tree Bindings
+
+maintainers:
+  - Iwona Winiarska <iwona.winiarska@intel.com>
+  - Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
+
+allOf:
+  - $ref: peci-controller.yaml#
+
+properties:
+  compatible:
+    enum:
+      - aspeed,ast2400-peci
+      - aspeed,ast2500-peci
+      - aspeed,ast2600-peci
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    description:
+      Clock source for PECI controller. Should reference the external
+      oscillator clock.
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  cmd-timeout-ms:
+    minimum: 1
+    maximum: 1000
+    default: 1000
+
+  clock-frequency:
+    description:
+      The desired operation frequency of PECI controller in Hz.
+    minimum: 2000
+    maximum: 2000000
+    default: 1000000
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - resets
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/ast2600-clock.h>
+    peci-controller@1e78b000 {
+      compatible = "aspeed,ast2600-peci";
+      reg = <0x1e78b000 0x100>;
+      interrupts = <GIC_SPI 38 IRQ_TYPE_LEVEL_HIGH>;
+      clocks = <&syscon ASPEED_CLK_GATE_REF0CLK>;
+      resets = <&syscon ASPEED_RESET_PECI>;
+      cmd-timeout-ms = <1000>;
+      clock-frequency = <1000000>;
+    };
+...