lsb: Use new WEBOS_DISTRO_* build info variables

[GF-2542] Change lsb_4.1.bbappend to use build related variables.

Open-webOS-DCO-1.0-Signed-off-by: Janne Hurskainen <janne.hurskainen@palm.com>
Change-Id: Ibecb06dc8431b02831f4422df528f080d3abad65
Reviewed-on: https://g2g.palm.com/1784
Reviewed-by: Herb Kuta <herb.kuta@lge.com>
Reviewed-by: Build Verification
Reviewed-by: Susan Montooth <susan.montooth@lge.com>
Reviewed-by: Martin Jansa <martin.jansa@palm.com>
Reviewed-by: Janne Hurskainen <janne.hurskainen@palm.com>
Tested-by: Janne Hurskainen <janne.hurskainen@palm.com>
Reviewed-by: Keith Derrick <keith.derrick@lge.com>