Add fractional divider support for RMT hal

[Tnze]

Thank you for your contribution!

We appreciate the time and effort you've put into this pull request.
To help us review it efficiently, please ensure you've gone through the following checklist:

Submission Checklist 📝

• I have updated existing examples or added new ones (if applicable).
• I have used cargo xtask fmt-packages command to ensure that all changed code is formatted correctly.
• My changes were added to the CHANGELOG.md in the proper section.
• I have added necessary changes to user code to the Migration Guide.
• My changes are in accordance to the esp-rs API guidelines

Extra:

• I have read the CONTRIBUTING.md guide and followed its instructions.

Pull Request Details 📖

Description

The hardware support fractional divider, but the HAL doesn't use it. We can use it to achieve higher accuracy.

Testing

Describe how you tested your changes.

Didn't test yet

[Tnze]

The solver from lcd_cam use Farey Sequence to find the closest fractional number.

Using Stern-Brocot Tree might be a better solution with O(log²V) complexity which V is the maximum limit of denominator.

[Tnze]

Current implementation is tested on ESP32-H2 which successfully dividing 32MHz resulted in 152kHz.