First set of IIO fixes for the 5.2 cycle.
* ads124
- Avoid a buffer overrun when setting an array to 0.
* ads8688
- Don't use the pollfunc timestamp as it isn't set and would be wrong
anyway for a device that does sampling on demand.
* ds4422
- Fix masking on register used for chip verification. Wrong address
was being read.
* mpu6050
- Fix the fifo layout for ICM20602 to avoid underreading and hence failure
to move on to the next record in the fifo.
* NPCM ADC
- Make sure there is actually a valid regulator before reading its voltage.