I figured out that you can not directly use a FTM block to trigger an ADC. It has to be done by a PDB (or PIT, RTC which I have not tried yet).
Did someone has successful implement the ADC_LDD and PDB_Init component to work together. All the examples that are distributed uses ADC_Init and PDB_Init to get them work together. However, then your are loosing all the Methods that make live easier to work with the ADC.