dt-bindings: input: Add binding for cypress-sf

Add a device tree binding for Cypress StreetFighter.

Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210907174341.422013-3-y.oudjana@protonmail.com


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