dt-bindings: iio: accel: Add SCA3300 documentation

initial DT bindings for Murata SCA3300 Accelerometer.
Signed-off-by: Tomas Melin <tomas.melin@vaisala.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210426081041.59807-2-tomas.melin@vaisala.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/accel/murata,sca3300.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/accel/murata,sca3300.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Murata SCA3300 Accelerometer
+
+description: |
+  3-axis industrial accelerometer with digital SPI interface
+  https://www.murata.com/en-global/products/sensor/accel/sca3300
+
+maintainers:
+  - Tomas Melin <tomas.melin@vaisala.com>
+
+properties:
+  compatible:
+    enum:
+      - murata,sca3300
+
+  reg:
+    maxItems: 1
+
+  spi-max-frequency:
+    maximum: 8000000
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        accelerometer@0 {
+            compatible = "murata,sca3300";
+            reg = <0x0>;
+            spi-max-frequency = <4000000>;
+        };
+    };
+...