talloc: Fix swig interface install path

Using the way swig interface is installed leads to a bad path in ${D}.
The interface ended up in ${D}/${STAGING_DIR_NATIVE} which is wrong. The
fix is to define a variable in recipe which is used in install rule by
talloc.
As well, LICENSE variable  modified to reflect the real license:
LGPL-3.0

Signed-off-by: Andrei Gherzan <andrei@gherzan.ro>
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>