The default controls are basically a 1:1 mapping with Playstation 1 Dualshock controls:
Wii U -> Playstation
Left analog = Left analog
Right analog = Right analog
Directional pad = Directional pad
Left stick button = L3
Right stick button = R3
Select = Select
Start = Start
X = Triangle
A = Circle
B = Cross
Y = Square
L = L1
ZL = L2
R = R1
ZR = R2