Added .dma_buffer to bypass DTCM

[MasterUser43]

Description

This PR updates the STM32H7 linker script (LinkerScript.ld) to define a .dma_buffer section allocated in the RAM_D2 memory.

This change is required because the STM32H7's DTCM RAM is unreachable by the DMA1 and DMA2 controllers.

Honestly, this is more as a reminder in the future for proper IMU function Rev 3.

Issue Link

Child PR, Parent PR:

Testing

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

If a non-automated test was executed that provides an artifact, please attach below (e.g. flash extract data).

Other

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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

Accuracy

• Code implements the correct requirement (a.k.a. does the right thing)
• Code is logically correct (a.k.a. does the thing right)

Error Handling

• Potentially unsafe functions return a status code
• Error returns properly handled
• Fail-fast errors are only thrown when unsafe to continue software execution
• Debug errors are thrown for exceptions where execution should still continue (to be noticed during development)

Memory

• Stack allocated memory is scoped correctly
• Heap allocated memory is not used
• Statically/Globally allocated memory is minimized except when necessary
• Pointers are used correctly
• Concurrent access has been considered (especially by/from interrupt service routines)

Performance

• Rate limiters are respected
• Busy waiting is avoided in performance sensitive code
• "Delay" calls are not used in performance sensitive code
• If performance is negatively impacted, a justification is provided and the impact is quantified

[ETSells]

Please pull up the driver and lib submodule pointers so I can see the CI results after all three PRs.

[ETSells]

CI fails associated with this PR appear to be due to a mismatch between the base versions of FCF and driver (e.g. driver is older than FCF & mod and does not supply a utility that FCF is expecting). Recommend either rebasing against the tip of main on each of your branches OR merging the tip of main into each of your branches.

Referencing: https://github.com/SunDevilRocketry/Flight-Computer-Firmware/actions/runs/28071241931/job/83106046527?pr=291

[MasterUser43]

This is what I get for moving from laptop to laptop to computer repos.

Still await slightly more changes w/ IMU, should at bare, compile with rev3.
make -j$(nproc)