Pdm constr init deinit

[NikhitaR-IFX]

Summary

• Enabled machine.PDM_PCM module with:

1. Constructor
2. init
3. deinit

There will be additional changes as I implement the read function. But so far, only initialization related parts are added. I am trying to follow the extmod/i2s way of doing this and open to suggestions if you feel the need to do any other way.

• Added tests for enabled functions.
• Added respective documentation.

Testing

• The HIL test might be failing for I2S but this is only because a change needed in .exp as clock is changed from different value now. I will fix that.
• @jaenrig-ifx : At times network_config.py test is as well failing in this branch but I have not changed anything there. Would it be possible for you to check once on your side?

[jaenrig-ifx]

Good progress already. Clean and neat 😺
A few things we can rework before merging. Others, maybe postpone 👍

[github-actions]

Code size report:

   bare-arm:    +0 +0.000% 
minimal x86:    +0 +0.000% 
   unix x64:    +0 +0.000% standard
      stm32:   +48 +0.012% PYBV10
     mimxrt:   +44 +0.012% TEENSY40
        rp2:   +48 +0.005% RPI_PICO_W
       samd:   +48 +0.018% ADAFRUIT_ITSYBITSY_M4_EXPRESS

[jaenrig-ifx]

Yep, let´s try to solve the freq changes introduced error in the PR, after our discussions.

[IFX-Anusha]

Nice !

[NikhitaR-IFX]

I will merge the branch now. @ramya-subramanyam you can also check the changes in machine-pdm branch.