ledc_write max_duty bug

[scrtrees]

https://github.com/espressif/arduino-esp32/blame/9e2f75564127a9853f80f3eb637b264406cb2f30/cores/esp32/esp32-hal-ledc.c#L181

//Fixing if all bits in resolution is set = LEDC FULL ON
    uint32_t max_duty = (1 << bus->channel_resolution) - 1;

    if ((duty == max_duty) && (max_duty != 1)) {
      duty = max_duty + 1;

If a user want to set resolution as 5 and set duty 31/32, it should be failed.
Duty ratio should be like as below.

channel_resolution = 5, duty = 0 → duty ratio = 0/32
channel_resolution = 5, duty = 1 → duty ratio = 1/32
channel_resolution = 5, duty = 2 → duty ratio = 2/32
...
channel_resolution = 5, duty = 30 → duty ratio = 30/32
channel_resolution = 5, duty = 31 → duty ratio = 31/32
channel_resolution = 5, duty = 32 → duty ratio = 32/32

However, current code makes it like below.

channel_resolution = 5, duty = 31 → duty ratio = 32/32 -> WRONG RATIO
channel_resolution = 5, duty = 32 → duty ratio = 32/32

The code on top just need to be deleted.

[SuGlider]

Looking into the LEDC documentation, we can verify that the Duty goes from 0 to 2^resolution.
Using 5 buts resolution, duty goes from 0 to 32 (33 levels).
Duty 0 = 0% ... Duty = 32 = 100%.

But... Arduino API says that Duty shoud go from 0 to (2^resolution) - 1.
Therefore, for Arduino API compatibility, the resolution is 5 bits is like this:
Duty 0 = 0% ... Duty 31 = 100%.

Thus, we have a different metric for resolution.
In such case, ESP32 Arduino Core has decided to implement the Arduino API metric system.

channel_resolution = 5, duty = 31 → duty ratio = 32/32 -> Arduino API compatible
channel_resolution = 5, duty = 32 → duty ratio = 32/32 -> IDF comaptible

[SuGlider]

@scrtrees - What we could change here is that ledcWrite() could act as IDF defines (0..32) and analogWrite() act as Arduino defines (0..31). In that case, duty = 31 would behave as 100%, mapping it to a ledcWrite(pin, 32).

In other words, the code you have pointed out shall be moved to analogWrite() and removed from ledcWrite().