firewallmngr: Added Device.Firewall.Type

* Added readonly param Device.Firewall.Type.

src/firewall.c

@@ -614,6 +614,12 @@ static int get_firewall_service_number_of_entries(char *refparam, struct dmctx *
 	return 0;
 }
 
+static int get_firewall_type(char *refparam, struct dmctx *ctx, void *data, char *instance, char **value)
+{
+	*value = "Stateful";
+	return 0;
+}
+
 static int get_level_alias(char *refparam, struct dmctx *ctx, void *data, char *instance, char **value)
 {
 	struct dm_data *p = (struct dm_data *)data;
@@ -2541,6 +2547,7 @@ DMLEAF tFirewallParams[] = {
 {"ChainNumberOfEntries", &DMREAD, DMT_UNINT, get_firewall_chain_number_of_entries, NULL, BBFDM_BOTH},
 {"DMZNumberOfEntries", &DMREAD, DMT_UNINT, get_firewall_dmz_number_of_entries, NULL, BBFDM_BOTH},
 {"ServiceNumberOfEntries", &DMREAD, DMT_UNINT, get_firewall_service_number_of_entries, NULL, BBFDM_BOTH},
+{"Type", &DMREAD, DMT_STRING, get_firewall_type, NULL, BBFDM_BOTH},
 {0}
 };