No. Holes in a PCB are essentially just cylinders drilled perpenficulsr to the surface of the board right through the PCB material by a vertical drill. There is no way to specify that a larger diameter drill can be applied to the same hole but to a lesser depth such as is required to drill a countersunk hole. You can define an M3 clearance hole but you cannot define any countersinking around the hole. That said you may be able to create something like a stepped hole by a milling process but you would need to contact the PCB manufacturer directly and EasyEDA Std has no particular features to support this.