nfd: Add nfd-dbg package with debug symbols of nfd and other binaries

Change-Id: Ic7b37f6527e4ff34418f31f09cc33b42086f3499
Refs: #11
diff --git a/nfd/Makefile b/nfd/Makefile
index e9a053b..6e441c8 100644
--- a/nfd/Makefile
+++ b/nfd/Makefile
@@ -11,6 +11,6 @@
 VERSION=0.4.0
 
 # PPA version
-PPA_VERSION=2
+PPA_VERSION=3
 
 include ../packaging.mk