dt-bindings: clock: tegra124-dfll: Convert to json-schema

Convert the Tegra124 (and later) DFLL bindings from the free-form text
format to json-schema.

Co-developed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Author: thierryreding