dt-bindings: watchdog: qcom-wdt: add QCM2290

Document the QCM2290 KPSS watchdog.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230314-topic-2290_compats-v1-1-47e26c3c0365@linaro.org


[groeck: Fixed context conflicts]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>