dt-bindings: watchdog: Document Google gs101 watchdog bindings

dt-bindings: watchdog: Document Google gs101 watchdog bindings

Add the "google,gs101-wdt" compatible to the dt-schema documentation.

gs101 SoC has two CPU clusters and each cluster has its own dedicated
watchdog timer (similar to exynos850 and exynosautov9 SoCs).

These WDT instances are controlled using different bits in PMU
registers.

Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Link: https://lore.kernel.org/r/20231211162331.435900-2-peter.griffin@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>