Allow to use libraries

Some binaries need to be copied with shared libraries.
Export LD_LIBRARY_PATH variable allows to put and use needed
libraries from `$TESTDIR/$ARCH/lib` directory.

Signed-off-by: Denis Pynkin <denis.pynkin@collabora.com>

update-test-path

@@ -12,4 +12,5 @@ aarch64) ARCHDIR=arm64 ;;
 esac
 
 PATH=${TESTPATH}/${ARCHDIR}/bin:$PATH
+export LD_LIBRARY_PATH=${TESTPATH}/${ARCHDIR}/lib:$LD_LIBRARY_PATH