dt-bindings: clock: Add BCM63268 timer binding

Document the Broadcom BCM63268 Clock and Reset controller.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230322171515.120353-4-noltari@gmail.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>