Replace CTLFLAG_NEEDGIANT with CTLFLAG_MPSAFE for all ADC sensor
sysctls. The driver uses I2C bus transfers which handle locking
internally via the I2C bus layer.
Sysctls converted:
- dev.ads111x.X.channelN.gain_index (PGA setting)
- dev.ads111x.X.channelN.rate_index (sample rate)
- dev.ads111x.X.channelN.voltage (sampled voltage)
- dev.ads111x.X.config (configuration register)
- dev.ads111x.X.lo_thresh (comparator low threshold)
- dev.ads111x.X.hi_thresh (comparator high threshold)