This adds support for this series' 14 bit accelerometer chip, MMA8451Q.
It's datasheet is available at the vendor's website:

https://cache.freescale.com/files/sensors/doc/data_sheet/MMA8451Q.pdfSigned-off-by: NMartin Kepplinger <martin.kepplinger@theobroma-systems.com>
Signed-off-by: NChristoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>