libffi: new package

libffi is needed by the Python interpreter.

The libffi library provides a portable, high level programming
interface to various calling conventions. This allows a programmer to
call any function specified by a call interface description at
run-time.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
diff --git a/package/Config.in b/package/Config.in
index 48f245c..4f1621b 100644
--- a/package/Config.in
+++ b/package/Config.in
@@ -327,6 +327,7 @@
 source "package/libdaemon/Config.in"
 source "package/libelf/Config.in"
 source "package/libevent/Config.in"
+source "package/libffi/Config.in"
 source "package/libglib2/Config.in"
 source "package/liboil/Config.in"
 source "package/libsigc/Config.in"