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.ua


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>