net: Express LINK_LOCAL dependency on LIB_RAND

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index e283cb9..1eb55e5 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1219,6 +1219,7 @@
 
 config CMD_LINK_LOCAL
 	bool "linklocal"
+	select LIB_RAND
 	help
 	  Acquire a network IP address using the link-local protocol