qt-in-industrial-embedded-smarthome: correct smarthome binary path

Tested on imx6qsabresd machine. Solves bug:
https://bugzilla.yoctoproject.org/show_bug.cgi?id=3571

[YOCTO #3571]

Signed-off-by: Leonardo Sandoval <leonardo.sandoval@freescale.com>
qt-in-industrial-embedded-common.inc: Use ${datadir} to adjust the .desktop path

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
README: Point to the official Yocto git tree

Signed-off-by: Leonardo Sandoval <leonardo.sandoval@freescale.com>