dt-bindings: hwmon: Add IBM OCC bindings

These bindings describe the POWER processor On Chip Controller accessed
from a service processor or baseboard management controller (BMC).
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20220809200701.218059-2-eajames@linux.ibm.comSigned-off-by: Joel Stanley <joel@jms.id.au>

Documentation/devicetree/bindings/hwmon/ibm,occ-hwmon.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/ibm,occ-hwmon.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: IBM On-Chip Controller (OCC) accessed from a service processor
+
+maintainers:
+  - Eddie James <eajames@linux.ibm.com>
+
+description: |
+  The POWER processor On-Chip Controller (OCC) helps manage power and
+  thermals for the system. A service processor or baseboard management
+  controller can query the OCC for it's power and thermal data to report
+  through hwmon.
+
+properties:
+  compatible:
+    enum:
+      - ibm,p9-occ-hwmon
+      - ibm,p10-occ-hwmon
+
+  ibm,no-poll-on-init:
+    description: This property describes whether or not the OCC should
+      be polled during driver initialization.
+    type: boolean
+
+required:
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |
+    hwmon {
+        compatible = "ibm,p10-occ-hwmon";
+        ibm,no-poll-on-init;
+    };