BTS_Tests.ttcn: add TC_pcu_ext_rach_content() for 11-bit RACH

According to 3GPP TS 04.60, section 11.2.5a, the extended (11-bit)
Access Burst on RACH/PRACH is used by the MS to indicate its EGPRS
capability. One of the alternative synch. sequences (see 3GPP TS
05.02, TS1 and TS2) shall be used.

Add a test case to verify extended (11-bit) RACH decoding.

Depends: (OsmocomBB) I36fd20cd5502ce33c52f644ee4c22abb83350df8
Change-Id: I8fe156aeac9de3dc1e71a4950821d4942ba9a253
Related: OS#1854
diff --git a/bts/expected-results.xml b/bts/expected-results.xml
index 2eadffd..7d89da3 100644
--- a/bts/expected-results.xml
+++ b/bts/expected-results.xml
@@ -77,6 +77,7 @@
   <testcase classname='BTS_Tests' name='TC_pcu_data_req_agch' time='MASKED'/>
   <testcase classname='BTS_Tests' name='TC_pcu_data_req_imm_ass_pch' time='MASKED'/>
   <testcase classname='BTS_Tests' name='TC_pcu_rach_content' time='MASKED'/>
+  <testcase classname='BTS_Tests' name='TC_pcu_ext_rach_content' time='MASKED'/>
   <testcase classname='BTS_Tests' name='TC_pcu_paging_from_rsl' time='MASKED'/>
   <testcase classname='BTS_Tests' name='TC_dyn_osmo_pdch_act_deact' time='MASKED'/>
   <testcase classname='BTS_Tests' name='TC_dyn_osmo_pdch_unsol_deact' time='MASKED'/>