VTY: add extended (11-bit) RACH detection toggle

Since I838c21db29c54f1924dd478c2b34b46b70aab2cd we have both TS1
and TS2 synch. sequences, in addition to "default" TS0. Let's
finally introduce the VTY configuration parameter, that can
be used to toggle optional detection of both TS1 and TS2.

Note: we keep this optional because of potentially bad impact on
performance. There's no point in paying the performance penalty
unless upper levels (BTS, PCU) actually make use of it.

Change-Id: I1aee998d83b06692d76a83f79748f9129a2547e8
Related: OS#3054
diff --git a/CommonLibs/trx_vty.h b/CommonLibs/trx_vty.h
index c921722..8d251ee 100644
--- a/CommonLibs/trx_vty.h
+++ b/CommonLibs/trx_vty.h
@@ -57,6 +57,7 @@
 		double offset;
 		double rssi_offset;
 		bool swap_channels;
+		bool ext_rach;
 		bool egprs;
 		unsigned int sched_rr;
 		unsigned int num_chans;