Makefile: use pkg/$MAIN_NAME/debian for defs

- if pkg/$MAIN_NAME/debian dir exists use it to build debs, otherwise
  use pkg/debian

Makefile

@@ -810,6 +810,10 @@ bin:
 deb:
 	-@if [ -d debian ]; then \
 		dpkg-buildpackage -rfakeroot -tc; \
+	elif [ -d pkg/$(MAIN_NAME)/debian ]; then \
+		ln -s pkg/$(MAIN_NAME)/debian debian; \
+		dpkg-buildpackage -rfakeroot -tc; \
+		rm debian; \
 	else \
 		ln -s pkg/debian debian; \
 		dpkg-buildpackage -rfakeroot -tc; \