egprs: Add CPS tables from TS 04.60

Includes EGPRS coding and puncturing scheme (CPS) tables from 3GPP
TS 04.60. Currently osmo-bts-trx is the only user of CPS table
values, but this may change with gprsdecode and other utilities.

Change-Id: I09fe6514a0e2e51bb3206f8387633f7e0255345f
5 files changed