Add initial MPU9150 compass support in core driver, not yet complete or tested
More MPU9150 compass WIP; bypass working, compass can be seen
Enable I2C master for aux bus, FIFO seems to be working for all data
Partially working MPU9150 slave driver, some corrupt data still present and healthy being forced
MPU9150 slave compass support working, needs updated INS driver
Set up MPU9150 for compass bypass capability, both accel/gyro and compass working
Update healthy criteria and make read I2C semaphore blocking (with timeout)
Refactor AK8975 compass driver slaved to MPU9150, remove dependencies
Merge branch 'mpu9150-compass' into trace-bringup