dt-bindings: reset: Add T-HEAD TH1520 SoC Reset Controller

dt-bindings: reset: Add T-HEAD TH1520 SoC Reset Controller

Add a YAML schema for the T-HEAD TH1520 SoC reset controller. This
controller manages resets for subsystems such as the GPU within the
TH1520 SoC.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
Link: https://lore.kernel.org/r/20250303152511.494405-2-m.wilczynski@samsung.com
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>