Prune some dead, unreachable code from our drivers

[ETSells]

Description

Prunes some dead code from old drivers.

Draft for now -- I'm re-running CI so I can find anything else I might need.

Issue Link

Part of SunDevilRocketry/Flight-Computer-Firmware#275

Testing

• Passes existing unit tests
• Unit tests modified
• Integration test performed

Attach any test artifacts here, if relevant.

Other

Leave any additional notes here

Reviewer Checklist

Standards

• Follows FCF Architectural Standards
• Follows SDR Coding Standards
• Code complexity/function Size is minimized
• Code is testable
• Code is readable and commented properly
• License terms are respected

Error Handling

• Potentially unsafe functions return a status code
• Error returns properly handled

Memory

• Stack allocated memory is scoped correctly
• Heap allocated memory is avoided
• Globally allocated memory is minimized except when necessary
• Pointers are used correctly
• Concurrency has been considered

Performance

• Rate limiters are respected
• Busy waiting is avoided
• "Delay" calls are not used in performance sensitive code