iio: mma8452: refactor for seperating chip specific data

This adds a struct mma_chip_info to hold data that will remain specific to
the chip in use. It is provided during probe() and linked in
struct of_device_id.

Also this suggests that the driver is called "mma8452" and now handles the
MMA8452Q device, but is not limited to it.
Signed-off-by: Martin Kepplinger <martin.kepplinger@theobroma-systems.com>
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>