preliminary ip.access BTS support, as of now only OML singalling works

diff --git a/include/openbsc/e1_input.h b/include/openbsc/e1_input.h
index 29c29d0..68b8d63 100644
--- a/include/openbsc/e1_input.h
+++ b/include/openbsc/e1_input.h
@@ -75,6 +75,11 @@
 			/* mISDN driver has one fd for each ts */
 			struct bsc_fd fd;
 		} misdn;
+		struct {
+			/* ip.access driver has one fd for each ts */
+			struct bsc_fd fd;
+		} ipaccess;
+
 	} driver;
 };