Please note - I am saying that ATP is not required to provide energy, but I am not saying that the reaction does not require energy at all! Any chemical reaction, (especially a large molecule shaped reaction such as digestion, which is mostly done in several steps) needs to be activated before the reaction can start, and activation requires energy, and the higher the required activation energy, the slower the reaction will be. The role of the catalyst - the enzyme in the digestion process - is to lower the activation energy required for the reaction, thereby increasing the reaction rate. So even though the hydrolysis of starch is an exothermic process, meaning that more energy is ultimately released than is initially absorbed, process-wise, energy is still required. But this energy is provided through heat within the digestive tract and does not need to be provided additionally.
Don't know if the answer is detailed enough~
FYI :-)