dt-bindings: iio: magnetometer: bmc150: Document mount-matrix

Document the mount-matrix property, which is used in device trees such
as msm8916-samsung-fortuna-common.dtsi, and supported by the driver.
Signed-off-by: Rayyan Ansari <rayyan.ansari@linaro.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20240716132512.80337-1-rayyan.ansari@linaro.orgSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/magnetometer/bosch,bmc150_magn.yaml

@@ -36,6 +36,9 @@ properties:
   interrupts:
     maxItems: 1
 
+  mount-matrix:
+    description: an optional 3x3 mounting rotation matrix.
+
 additionalProperties: false
 
 required: