package/swupdate: add comment on origin of services/configs

Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
(cherry picked from commit 7b1bdc3cee0506c477ed92e02d2ac14137bfc076)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/swupdate/swupdate.mk

@@ -195,6 +195,8 @@ $(error No Swupdate configuration file specified, check your BR2_PACKAGE_SWUPDAT
 endif
 endif
 
+# Services and configs derived from meta-swupdate(MIT license)
+# https://github.com/sbabic/meta-swupdate/tree/master/recipes-support/swupdate/swupdate
 define SWUPDATE_INSTALL_COMMON
 	mkdir -p $(TARGET_DIR)/etc/swupdate/conf.d \
 		$(TARGET_DIR)/usr/lib/swupdate/conf.d