[Docs] Add section about EEPROM on ARM

[yanfali]

Document ARM EEPROM issues in FAQ

Description

Provide guidance for users of ARM based QMK boards

Types of changes

• Core
• Bugfix
• New Feature
• Enhancement/Optimization
• Keyboard (addition or update)
• Keymap/Layout/Userspace (addition or update)
• Documentation

Issues Fixed or Closed by this PR

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document. (https://docs.qmk.fm/#/contributing)
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[drashna]

Also, it should be noted that the compiled images above may need to be updated in the future.

And that i'm the one that compiled them, and all I did was add eeconfig_init() to matrix_init_user(), so you will want to reflash "your" firmware, after flashing these ones

[yiancar]

I also think instead of linking .bin for specific folders we could generate a general bin that would just do an erase eeprom.

[drashna]

@yiancar the bin's are more of a stopgap for the boards that are definitely having this issue.

If it's possible, it would be nice to have a dfu-util command to reset the eeprom. If that's a bin, that's fine too.

[yiancar]

Just flashing a .bin full of 0xff would erase the whole of the flash (and therefor the "eeprom")

[drashna]

Like completely 0xFF, or with addresses, etc?

Aka, do you have such a hex?