iio: accel: bmi088: Add support for bmi085 accel

iio: accel: bmi088: Add support for bmi085 accel

Add supports for BMI085, an Inertial Measurement Unit,
with an accelerometer and gyroscope.
The commit adds the accelerometer driver for the SPI interface.
The gyroscope part is already supported by the BMG160 driver.
Unlike BMI088, the BMI085 accelerometer ranges are +/-2, 4, 6,
and 8g, the scales are calculated as 9.8/32768*pow(2,reg41+1).

Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
Link: https://lore.kernel.org/r/20220526133359.2261928-5-Qing-wu.Li@leica-geosystems.com.cn
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>