no. no it isn't. the power supply doesn't only run the cpu but everything in your system. the psu's power output will degrade over time as well so you don't want to be right at the bleeding edge anyway. if you won't be running a graphics card, i'd recommend no less than a 300w PSU.
Reason being, even if nothing else in the computer used power, the cpu's power draw will go up and down depending on load and may go beyond 100w
As a side note, I'd consider using a cheap aftermarket cooler if at all possible. The stock cooler for the APUs are not that great when using the ingrated graphics.