Hello Anil Kumar and Do Nam,
Updating this thread, the QMAKE_LFLAGS does points to the correct libraries. However, the root cause of this issue is that the architecture is not matching the libraries, which seemed odd.
If you look at the Makefile created by qmake it was not using the correct toolchain.
The way to give qmake the right parameters to build is by using a qmake configuration file. You would need to add the linux-arm-gnueabi-g++ spec on:
/opt/<DISTRO>/<VERSION>/sysroots/cortexa9hf-vfp-neon-poky-linux-gnueabi/usr/lib/qt5/mkspecs/
You should have several specs. On this same folder create the linux-arm-gnueabi-g++ spec folder and create the qmake.conf and qplatformdefs.h:
/opt/<DISTRO>/<VERSION>/sysroots/cortexa9hf-vfp-neon-poky-linux-gnueabi/usr/lib/qt5/mkspecs/ linux-arm-gnueabi-g++/qmake.conf
/opt/<DISTRO>/<VERSION>/sysroots/cortexa9hf-vfp-neon-poky-linux-gnueabi/usr/lib/qt5/mkspecs/ linux-arm-gnueabi-g++/qplatformdefs.h
I have attached the format of both. You may leave the gplatformdefs.h untouched and just edit qmake.conf so it has the right path for the sysroot on your system.
Then on the Kits settings under Qt mkspec you would need to write: linux-arm-poky-gnueabi-g++.

After setting all this up please make a clean and then run qmake and build again. It should be able to find the right libraries now.
Regards,