setup-environment: set default distro

* Set poky-ivi-systemd as default distro
* Correct target platform message for imx6qsabreauto
* Remove 4.0 from welcome message
* Update build target used in meta-ivi master branch

Signed-off-by: Adrian Alonso <aalonso@freescale.com>
README: remove genivi 4.0 from version description

* Remove Genivi 4.0 from version description

Signed-off-by: Adrian Alonso <aalonso@freescale.com>
bblayers: update meta-ivi layer path

* Update meta-ivi layer path to
  ${BSPDIR}/sources/meta-ivi/meta-ivi to follow
  new meta-ivi directory structure (master branch)

Signed-off-by: Adrian Alonso <aalonso@freescale.com>