Create driver for the MMA8451Q accelerometer sensor on FRDM-KL25Z

[larsgk]

Inspiration: https://os.mbed.com/users/emilmont/code/MMA8451Q/file/c4d879a39775/MMA8451Q.cpp/

I might look into this myself. Do I need to sign an online NDA/code collab doc?

[MaureenHelm]

Do I need to sign an online NDA/code collab doc?

No. http://docs.zephyrproject.org/contribute/contribute_guidelines.html

[larsgk]

(working on this + a sample app to join it at the moment)