dt-bindings: iio: accel: bma255: Document bosch,bma253

dt-bindings: iio: accel: bma255: Document bosch,bma253

BMA253 is mostly like BMA255 that is already supported by the
bmc150-accel driver. Document an extra bosch,bma253 compatible for it.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20210611080903.14384-7-stephan@gerhold.net
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>