Managed to get rid of this error by using an externally installed copy of make in place of the one found within the NXP folder.
In the project Properties (File > Properties, or right click on project > Properties) expand C/C++ and go to Environment. Edit (or add) the PATH variable to include the path to the bin folder of your external Make installation at the beginning of the list. This bin folder would be the one containing the make.exe executable. Apply and Close. Rebuild.