install libs to cmake variable not lib

Was needed for multi arch support (x86_64)

Bug: http://bugs.genivi.org/show_bug.cgi?id=235
Bug-Tizen: TC-1208/related
Origin: http://bugs.genivi.org/attachment.cgi?id=89
Change-Id: I54578f4f320ce7ac5dc5b3116283731c7fca1e53
Signed-off-by: Philippe Coval <philippe.coval@open.eurogiciel.org>