Remove the older xtscal tool and start using the newer xinput-calibrator and ensure that it's part of the x11 image and tested. Ensure that libxcalibrate is still needed.
The (badly titled) bug 8380 needs to be fixed or worked around for this: otherwise the calibrator UI pops up on every qemu boot.
xtscal removal along with fix for 8380 was sent to oe-core mailing list: http://lists.openembedded.org/pipermail/openembedded-core/2016-June/122857.html
http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=be554d7e6ccfe120e3b004582442f3b76952fad0