vty/command: introduce new attribute CMD_ATTR_IMMEDIATE

This attribute indicates that a VTY command applies immediately.

Change-Id: Ia185dfd0c89214dc893af70736ff01dca3a7627e
Related: SYS#4937
diff --git a/include/osmocom/vty/command.h b/include/osmocom/vty/command.h
index 47d2e5f..43ad3da 100644
--- a/include/osmocom/vty/command.h
+++ b/include/osmocom/vty/command.h
@@ -137,6 +137,7 @@
 enum {
 	CMD_ATTR_DEPRECATED	= (1 << 0),
 	CMD_ATTR_HIDDEN		= (1 << 1),
+	CMD_ATTR_IMMEDIATE	= (1 << 2),
 };
 
 /*! Structure of a command element */