* `ledcWriteTone()` added a `apbcallback()` evertime the tone value was non zero.
* `addApbChangeCallback()` did not detect duplicate callbacks.
* changed the apbcallback list to a double link to support roll forward, roll back execution. This made the sequences of clock change callback start with the newest registered -> to oldest on the `before` then oldest -> newest after the clock change. This made the UART debug log output have minimal gibberish during the clock change.
* change how the UART callback handled the MUTEX because if any `apbchangeCallback()` executed a `log_x()` a deadlock would occur.
This fixes#3555
* Add APB change callbacks and move cpu code to own file
* Properly set esp_timer and FreeRTOS tick dividers
* Improve updated devisors
* No need to update REF_TICK yet
* Add initial handling for UART baud change
* fix uartWriteBuf and uartDetectBaudrate
* trigger callbacks even when APB did not change
* toggle UART ISR on CPU change
* add XTAL freq getter and add cpu freq validation
* Support CPU frequency changes in I2C (#2287)
**esp32-hal-i2c.c**
* add callback for cpu frequency changes
* adjust fifo thresholds based on cpu frequency and i2c bus frequency
* reduce i2c bus frequency if differential is too small
**Wire.h**
* version to 1.1.0
* Implement clock change for the other peripherals
* remove bad CPU clock values from the menu
* Add note to CPU freqs that support WiFi and BT
* Add support to HAL for APB frequencies different than 80MHz
* Add support for CPU frequencies in the IDE board menu
* Switch to fast set_config
* Add method to uart so debug can be reassigned after apb frequency switch
* Return real APB frequency
* Update mDNS and LEDC
* update toolchain
* Update IDF to 1c3dd23
* Advertise the board variant for Arduino OTA
* Add generic variant definition for mDNS
IDF Options:
- Autostart Arduino (implements app_main)
- Disable HAL locks
- Set HAL debug level
- Auto-connect STA if configured (else will connect after WiFi.begin())
