dt-bindings: iio: st,st-sensors: Add LSM9DS0 compatible string

Enumerate LSM9DS0 (accelerometer and magnetometer parts) via
'st,lsm9ds0-imu' compatible string.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210414195454.84183-7-andriy.shevchenko@linux.intel.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/st,st-sensors.yaml

@@ -75,6 +75,9 @@ properties:
           - st,lps331ap-press
           - st,lps33hw
           - st,lps35hw
+      - description: IMUs
+        enum:
+          - st,lsm9ds0-imu
       - description: Deprecated bindings
         enum:
           - st,lis302dl-spi