iio: chemical: bme680: Add triggered buffer support

iio: chemical: bme680: Add triggered buffer support

Add triggered buffer and soft timestamp support. The available scan mask
enables all the channels of the sensor in order to follow the operation of
the sensor. The sensor basically starts to capture from all channels
as long as it enters into FORCED mode.

The bulk read, reads a total of 15 registers from the sensor, 0x1D..0x2B.
Even though some of those registers are not reported in the register map
of the device, this is how the BME680 Sensor API [1] proposes to do it.
This allows to have one bulk read instead of multiple ones.

Link: https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/bme68x.c#L1200
Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
Link: https://patch.msgid.link/20241102131311.36210-4-vassilisamir@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>