Merge pull request #1155 from fkjagodzinski/docs_update-watchdog_clock

Update the watchdog timing requirements

Author: iriark01

docs/porting/target/Watchdog.md

@@ -11,8 +11,10 @@ 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 divided by max_frequency).
+- The calibrated watchdog should trigger at or after the timeout value.
 - The watchdog should trigger before twice the timeout value.
+- The watchdog may trigger as late as twice the timeout value in deep sleep mode.
 
 ### Undefined behavior