Use --quiet configure argument when make is invoked with the -s (silent) option.
@@ -215,6 +215,7 @@ $(BUILD_DIR)/%/.stamp_configured:
--prefix=/usr \
--exec-prefix=/usr \
--sysconfdir=/etc \
+ $(if $(findstring s,$(MAKEFLAGS)),--quiet,)
$($(PKG)_CONF_OPT)
$(Q)touch $@