dt-bindings: iio/accel: Drop duplicate adi,adxl345/6 from trivial-devices.yaml

The 'adi,adxl345' definition is a duplicate as there's a full binding in:
Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml

The trivial-devices binding doesn't capture that 'adi,adxl346' has a
fallback compatible 'adi,adxl345', so let's add it to adi,adxl345.yaml.
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: linux-iio@vger.kernel.org
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Jonathan Cameron <jic23@kernel.org>

Documentation/devicetree/bindings/iio/accel/adi,adxl345.yaml

@@ -17,9 +17,13 @@ description: |
 
 properties:
   compatible:
-    enum:
-      - adi,adxl345
-      - adi,adxl375
+    oneOf:
+      - items:
+          - const: adi,adxl346
+          - const: adi,adxl345
+      - enum:
+          - adi,adxl345
+          - adi,adxl375
 
   reg:
     maxItems: 1

Documentation/devicetree/bindings/trivial-devices.yaml

@@ -42,10 +42,6 @@ properties:
           - adi,adt7476
             # +/-1C TDM Extended Temp Range I.C
           - adi,adt7490
-            # Three-Axis Digital Accelerometer
-          - adi,adxl345
-            # Three-Axis Digital Accelerometer (backward-compatibility value "adi,adxl345" must be listed too)
-          - adi,adxl346
             # AMS iAQ-Core VOC Sensor
           - ams,iaq-core
             # i2c serial eeprom  (24cxx)