There are two ways to archive this:
Either with Yocto (There is already a layer with all configs done for you, meta-qt5) or cross-compiling against a LTIB rootfs. For the primer, please follow the meta-freescale distribution list, for the latter there is a page on the community, look for 'qt5' results (https://community.freescale.com/docs/DOC-94066?).
Leo