bts: Add LAPDm test for SABM with wrong C/R bit

Test that the BTS will take no action when it receives an SABM frame
with the C bit set wrong (R); Inspired by TS 51.010-1 25.2.5.2

Implemented as TC_sabm_incorrect_c().

Related: OS#4032
Change-Id: I4fbe7e708c9b1a2c04e5d24a205b5b5af20ff8c7
1 file changed