Remove rest_octets.h

The MSC should not fiddle with low-level SI details like rest octets
anyway. Unfortunately simply removing the header is impossible as it
causes massive fallout due to missing includes. Fixed it as well.

The only other parameter which required removal is cell_ro_sel_par which
is not referenced anywhere in the code anyway.

Change-Id: Ibff77330de056fad4288cd4c48d016aad8105354
diff --git a/src/libmsc/a_iface.c b/src/libmsc/a_iface.c
index 3e86494..4892fb8 100644
--- a/src/libmsc/a_iface.c
+++ b/src/libmsc/a_iface.c
@@ -40,6 +40,8 @@
 #include <osmocom/msc/a_reset.h>
 #include <osmocom/msc/osmo_msc.h>
 
+#include <errno.h>
+
 /* A pointer to the GSM network we work with. By the current paradigm,
  * there can only be one gsm_network per MSC. The pointer is set once
  * when calling a_init() */