Fix adc_oversample() where priv->trovs (a bool, 0 or 1) was OR'd
directly into setbits instead of using ADC_CFGR2_TROVS (bit 9).
This caused triggered oversampling to never actually be enabled.
Fix ANIOC_WDOG_UPPER and ANIOC_WDOG_LOWER ioctls where the TR1
register was overwritten with only the new threshold value, zeroing
out the opposite threshold and the AWDFILT digital filter bits.
Use read-modify-write to preserve the other fields.
Signed-off-by: kywwilson11 <kwilson@2g-eng.com>