Add MODESELECT6 support

Add support for MODESELECT6 and add marshalling functions for the
mode pages we support so far.

lib/sync.c

@@ -1156,6 +1156,26 @@ iscsi_scsi_command_sync(struct iscsi_context *iscsi, int lun,
 }
 
 
+struct scsi_task *
+iscsi_modeselect6_sync(struct iscsi_context *iscsi, int lun,
+		       int pf, int sp, struct scsi_mode_page *mp)
+{
+	struct iscsi_sync_state state;
+
+	memset(&state, 0, sizeof(state));
+
+	if (iscsi_modeselect6_task(iscsi, lun, pf, sp, mp,
+				  scsi_sync_cb, &state) == NULL) {
+		iscsi_set_error(iscsi,
+				"Failed to send MODE_SELECT6 command");
+		return NULL;
+	}
+
+	event_loop(iscsi, &state);
+
+	return state.task;
+}
+
 struct scsi_task *
 iscsi_modesense6_sync(struct iscsi_context *iscsi, int lun, int dbd,
 		      int pc, int page_code, int sub_page_code,