Add lsm6dsv320x-pid submodule to lib root (pair w/ IMU r3)

[MasterUser43]

Description

This PR adds the STMicroelectronics driver for the LSM6DSV320X (lsm6dsv320x-pid) as a git submodule under the library root directory (/lib).

This dependency provides the low-level register maps and driver context APIs utilized by the new imu_lsm.c/h implementation.

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Testing

• Passes existing unit tests
• Unit tests modified (link the test changes as a child PR)
• Integration test performed

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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

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