pkgconfig: Update pkgconfig file to include -framework directives

These are now necessary to build against static library

Change-Id: Ia03e3279a7583e8f387e864edcbb2ed32786f622
diff --git a/libndn-cpp-dev.pc.in b/libndn-cpp-dev.pc.in
index 0e31949..4b0e793 100644
--- a/libndn-cpp-dev.pc.in
+++ b/libndn-cpp-dev.pc.in
@@ -6,5 +6,5 @@
 Name: libndn-cpp-dev
 Description: Development version of C++ API for NDN (NDN-TLV packet format)
 Version: @VERSION@
-Libs: -L${libdir} @EXTRA_LDFLAGS@ -lndn-cpp-dev @EXTRA_LIBS@
+Libs: -L${libdir} @EXTRA_LDFLAGS@ -lndn-cpp-dev @EXTRA_LIBS@ @EXTRA_FRAMEWORKS@
 Cflags: -I${includedir} @EXTRA_INCLUDES@