Pass pass cross tools to make. Closes: #958227

Thanks Helmut Grohne for the report and the fix.

debian/rules

@@ -19,7 +19,7 @@ override_dh_clean:
 	dh_clean
 
 override_dh_auto_build:
-	$(MAKE) PLATFORM=$(PLATFORM)
+	dh_auto_build --no-parallel -- PLATFORM=$(PLATFORM)
 
 override_dh_auto_install:
 	$(MAKE) install prefix=debian/vblade/usr