[peripheral] start mpu driver
[mpu] attempt to make a generic configuration (spi/i2c)
[mpu] add i2c support for mpu60x0
[peripherals] rename mpu60x0 files
[peripherals] mpu60x0: use i2c convenience functions
Merge remote-tracking branch 'paparazzi/mpu60x0' into stm32f4
Merge remote-tracking branch 'paparazzi/stm32f4' into stm32f4
[apogee] add apogee imu based on mpu60x0