dt-bindings: Add vendor prefix and bindings for Qwiic Joystick

Add vendor prefix for SparkFun Electronics.
Update trivial-devices.yaml with SparkFun Qwiic Joystick description.
Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210608223130.16830-1-oleg@kaa.org.uaSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Documentation/devicetree/bindings/trivial-devices.yaml

@@ -261,6 +261,8 @@ properties:
             # Socionext SynQuacer TPM MMIO module
           - socionext,synquacer-tpm-mmio
             # i2c serial eeprom  (24cxx)
+          - sparkfun,qwiic-joystick
+            # SparkFun Qwiic Joystick (COM-15168) with i2c interface
           - st,24c256
             # Ambient Light Sensor with SMBUS/Two Wire Serial Interface
           - taos,tsl2550

Documentation/devicetree/bindings/vendor-prefixes.yaml

@@ -1060,6 +1060,8 @@ patternProperties:
     description: Sony Corporation
   "^spansion,.*":
     description: Spansion Inc.
+  "^sparkfun,.*":
+    description: SparkFun Electronics
   "^sprd,.*":
     description: Spreadtrum Communications Inc.
   "^sst,.*":