ESP32-C2 has a single group timer, thus it will use it for the interrupt watchdog,
which is more critical than the task watchdog. The latter is implement in
software thanks to the `esp_timer`component.
This commit updates the watchdog documentation as follows:
- Removes IWDT API reference as it is now considered private API
- Rewrite IWDT section
- Fix headers, types, and formatting
This commit moidifies the TWDT as follows:
- Adds a feature to allows subscribing arbitrary users to the TWDT
- Changes esp_task_wdt_init() API to accept configuration structure
- Changes esp_task_wdt_init() and esp_task_wdt_deinit() to subscribe/unsubscribe
idle tasks of various cores.
- Adds support for SMP FreeRTOS idle tasks
- Updates startup code TWDT initialization
- Updates API documentation
Moved the following kconfig options out of the target component:
* CONFIG_ESP*_DEFAULT_CPU_FREQ* -> esp_system
* ESP*_REV_MIN -> esp_hw_support
* ESP*_TIME_SYSCALL -> newlib
* ESP*_RTC_* -> esp_hw_support
Where applicable these target specific konfig names were merged into
a single common config, e.g;
CONFIG_ESP*_DEFAULT_CPU_FREQ -> CONFIG_ESP_DEFAULT_CPU_FREQ_MHZ
