Update the watchdog timing requirements

Update the requirements according to PR #11203 that differentiates lower
timeout limit for calibrated and uncalibrated watchdog clock.

Author: fkjagodzinski

docs/porting/target/Watchdog.md

@@ -11,7 +11,8 @@ Implement the ResetReason API when implementing the Watchdog API. The ResetReaso
 - Sleep and debug modes don't stop the watchdog timer from counting down.
 - The function `hal_watchdog_init` is safe to call repeatedly. The function's implementation must not do anything if `hal_watchdog_init` has already initialized the hardware watchdog timer.
 - `UINT32_MAX` milliseconds is the maximum allowed max_timeout `hal_watchdog_get_platform_features()` returns; minimum timeout is 1 ms.
-- The watchdog should trigger at or after the timeout value.
+- The uncalibrated watchdog should trigger at or after the timeout value multiplied by the frequency accuracy ratio of its oscillator (typical_frequency / max_frequency).
+- The calibrated watchdog should trigger at or after the timeout value.
 - The watchdog should trigger before twice the timeout value.
 
 ### Undefined behavior