AP_HAL_ChibiOS: add LSM6DSV IMU support for KakuteH7 boards

[zebulon-86]

Summary

Support LSM6DSV-family IMUs on KakuteH7 and KakuteH7Mini boards as an alternative to ICM42688.

Classification & Testing (check all that apply and add your own)

• Checked by a human programmer
• Non-functional change
• No-binary change
• Infrastructure change (e.g. unit tests, helper scripts)
• Automated test(s) verify changes (e.g. unit test, autotest)
• Tested manually, description below (e.g. SITL)
• Tested on hardware
• Logs attached
• Logs available on request

Test hardware: Kakute H7 Mini v1.5 and Kakute H7 v1.5

Description

Add an lsm6dsv SPI device on SPI4 for KakuteH7 and KakuteH7Mini. It is an alternative to the existing ICM42688 and shares the same chip-select line.

Add the existing LSM6DSV IMU probe entry with the board-specific orientation:

• KakuteH7: ROTATION_ROLL_180_YAW_270
• KakuteH7Mini: ROTATION_PITCH_180_YAW_90

This change only adds hwdef support; it does not change the shared LSM6DSV driver.

Hardware validation performed with an LSM6DSK320X:

1. The Mission Planner Messages view reports LSM6DSK320X fast sampling, confirming that the LSM6DSK320X is detected and started.

3. The accelerometer and gyro device IDs are both 4391458, with DevType = 67 (0x43). This matches DEVTYPE_INS_LSM6DSK320X.

4. Accelerometer calibration completed successfully on both boards. Physical orientation checks in the attitude view matched the displayed orientation, confirming the configured board rotations.

AI assistance: This PR description was drafted from the two hwdef commits and human-performed hardware test results. The contributor reviewed the change and performed the reported hardware validation.