vty: Document some previously undocumented parameters

Katerina pointed out that some nodes are not fully documented and
proposed some messages. The token/timeout messages were correct, I
have modified the other messages. I removed the full-stop from the
PING/PONG documentation as we are normally not using a full sentence.
diff --git a/openbsc/src/osmo-bsc/osmo_bsc_vty.c b/openbsc/src/osmo-bsc/osmo_bsc_vty.c
index fb38848..254a56c 100644
--- a/openbsc/src/osmo-bsc/osmo_bsc_vty.c
+++ b/openbsc/src/osmo-bsc/osmo_bsc_vty.c
@@ -180,7 +180,7 @@
 DEFUN(cfg_net_bsc_token,
       cfg_net_bsc_token_cmd,
       "token TOKEN",
-      "A token for the BSC to be sent to the MSC")
+      "A token for the BSC to be sent to the MSC\n" "A token\n")
 {
 	struct osmo_msc_data *data = osmo_msc_data(vty);
 
@@ -335,7 +335,8 @@
 DEFUN(cfg_net_msc_ping_time,
       cfg_net_msc_ping_time_cmd,
       "timeout-ping NR",
-      "Set the PING interval, negative for not sending PING")
+      "Set the PING interval, negative for not sending PING\n"
+      "Timeout in seconds\n")
 {
 	struct osmo_msc_data *data = osmo_msc_data(vty);
 	data->ping_timeout = atoi(argv[0]);
@@ -345,7 +346,7 @@
 DEFUN(cfg_net_msc_pong_time,
       cfg_net_msc_pong_time_cmd,
       "timeout-pong NR",
-      "Set the time to wait for a PONG.")
+      "Set the time to wait for a PONG\n" "Timeout in seconds\n")
 {
 	struct osmo_msc_data *data = osmo_msc_data(vty);
 	data->pong_timeout = atoi(argv[0]);