Hi ! I have the same problem. The QT included in the last IMG doesn't include a Qmake file. So when I compile like you, it give the same error cause we need to interface with the supplied proprietary libs in /opt I think.
On the Raspberry Pi, we need to interface with the VC libs in opt/ to correctly initialise with hardware acceleration, but VC libs are only for the Broadcom chipset on the Pi. On my NanoPI, it is a S5P4418, with a Nexell backend. Maybe we have to do the same with the Nexell libs included on the IMG ? I have a Fire2A and a S2, not sure you have the same configuration as me.
Qt recognize EGL and OpenGLES 2 but can't seem to open a display without these libs.