dt-bindings: iio: accel: bosch,bma255: add bmx055 accel binding

dt-bindings: iio: accel: bosch,bma255: add bmx055 accel binding

Add the device-tree binding for the Bosch BMX055 IMU (accelerometer part),
which is compatible with bmc150_accel.

Datasheet: https://cdn.sparkfun.com/assets/b/9/1/f/4/bst-bmx055-ds000_datasheet.pdf
Signed-off-by: Jun Yan <jerrysteve1101@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>