dt-bindings: interconnect: samsung,exynos-bus: convert to dtschema

Convert the Samsung Exynos SoC Bus and Interconnect bindings to DT
schema.

Vast parts of descritpion and example were copied, so keep license as
GPL-2.0-only.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>