iio: chemical: bme680: Use bulk reads for calibration data

Calibration data are located in contiguous-ish registers inside the chip.
For that reason we can use bulk reads as is done as well in the BME68x
Sensor API [1].

The arrays that are used for reading the data out of the sensor
are located inside DMA safe buffer.

Link: https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/bme68x.c#L1769

 # [1]
Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
Link: https://patch.msgid.link/20240609233826.330516-8-vassilisamir@gmail.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>