controller: Extract garp_rarp to engine node.

Previously on each call to pinctrl_run all addresses that need to be
announced via garps or rarps where computed newly. On larger external
networks that might take significant time.
However the content of the data can only change in a run of the I+P
engine. So we move the whole logic to an engine node and only handle the
minimal needed set in pinctrl_run.

Signed-off-by: Felix Huettner <felix.huettner@stackit.cloud>

controller/automake.mk

@@ -59,7 +59,9 @@ controller_ovn_controller_SOURCES = \
 	controller/route-exchange.h \
 	controller/route-table-notify.h \
 	controller/route.h \
-	controller/route.c
+	controller/route.c \
+	controller/garp_rarp.h \
+	controller/garp_rarp.c
 
 if HAVE_NETLINK
 controller_ovn_controller_SOURCES += \