After getting weird ADC readings with KSDK I found the ADC's were not being set up properly due to a few missing defines in LPC54016_features.h, also effects the 54018.
These are the missing defines I've found so far :
#define FSL_FEATURE_ADC_HAS_CTRL_RESOL (1)
#define FSL_FEATURE_ADC_HAS_CTRL_ASYNMODE (1)
#define FSL_FEATURE_ADC_HAS_CTRL_BYPASSCAL (1)
#define FSL_FEATURE_ADC_HAS_CTRL_TSAMP (1)