How to use a MOSFET driver directly to drive DC motors with PWM?
There is nothing in the datasheet that indicates that the gate driver could be used to source DC, but the operation was never intended for such:


  MOSFET drivers are high-speed, high-current device swhich are intended
  to source/sink high peak currents to charge/discharge  the  gate 
  capacitance  of  external MOSFETs or IGBTs.


Source: http://ww1.microchip.com/downloads/en/DeviceDoc/20002052D.pdf

Mosfet gates are high impedance, and only need current while switching. Using the gate driver in a constant mode at high current could cause failure. There is nothing in the datasheet to indicate this (there are no DC specs) because the designers did not intend or test it for DC use. 

I would use the MCP1402 to drive an h-bridge and use that to drive the motor.