kbuild: [bin]deb-pkg: add DPKG_FLAGS variable

DPKG_FLAGS variable lets user to add more flags to dpkg-buildpackage
command in deb-pkg and bindeb-pkg.
Signed-off-by: Kacper Kołodziej <kacper@kolodziej.it>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

scripts/package/Makefile

@@ -72,11 +72,11 @@ deb-pkg: FORCE
 	$(call cmd,src_tar,$(KDEB_SOURCENAME))
 	origversion=$$(dpkg-parsechangelog -SVersion |sed 's/-[^-]*$$//');\
 		mv $(KDEB_SOURCENAME).tar.gz ../$(KDEB_SOURCENAME)_$${origversion}.orig.tar.gz
-	+dpkg-buildpackage -r$(KBUILD_PKG_ROOTCMD) -a$$(cat debian/arch) -i.git -us -uc
+	+dpkg-buildpackage -r$(KBUILD_PKG_ROOTCMD) -a$$(cat debian/arch) $(DPKG_FLAGS) -i.git -us -uc
 
 bindeb-pkg: FORCE
 	$(CONFIG_SHELL) $(srctree)/scripts/package/mkdebian
-	+dpkg-buildpackage -r$(KBUILD_PKG_ROOTCMD) -a$$(cat debian/arch) -b -nc -uc
+	+dpkg-buildpackage -r$(KBUILD_PKG_ROOTCMD) -a$$(cat debian/arch) $(DPKG_FLAGS) -b -nc -uc
 
 intdeb-pkg: FORCE
 	+$(CONFIG_SHELL) $(srctree)/scripts/package/builddeb