package/bird: make RIP optional

In commit 529fef57f6f46201ba16349b49c0a65ceccc4c25 ("package/bird: add
optional protocols") we added options to conditionally enable
different protocol support. However, disabling the RIP support was not
working, so it remained forcefully enabled, and there was no
BR2_PACKAGE_BIRD_RIP option.

However, since the bump to 2.0.6 in commit
b9f43ade0fbce38b803214c167df52ca7fd3ee03, this issue has been fixed,
so we can introduce the BR2_PACKAGE_BIRD_RIP option, and make it
really optional.

Signed-off-by: Adrien Gallouët <adrien@gallouet.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/bird/Config.in

@@ -67,6 +67,11 @@ config BR2_PACKAGE_BIRD_RADV
 	help
 	  Enable RAdv protocol.
 
+config BR2_PACKAGE_BIRD_RIP
+	bool "rip"
+	help
+	  Enable RIP protocol.
+
 config BR2_PACKAGE_BIRD_STATIC
 	bool "static"
 	help

package/bird/bird.mk

@@ -17,9 +17,7 @@ else
 BIRD_CONF_OPTS += --disable-client
 endif
 
-# BUG: RIP is mandatory for now
 BIRD_PROTOCOLS = \
-	rip \
 	$(if $(BR2_PACKAGE_BIRD_BFD),bfd) \
 	$(if $(BR2_PACKAGE_BIRD_BABEL),babel) \
 	$(if $(BR2_PACKAGE_BIRD_BGP),bgp) \