libtool: remove build host paths from installed libtool

libtool: remove build host paths from installed libtool

Resulted libtool contains references about paths from the build host

Below variables contains hard coded build paths from the host:
LTCC=
lt_sysroot=
sys_lib_search_path_spec=
LD=
CC=
compiler_lib_search_dirs=
predep_objects=
postdep_objects=
compiler_lib_search_path=

Signed-off-by: Shiqun Lin <Shiqun.Lin@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>