bts: Fully implement TC_pcu_data_req_{pdtch,ptcch}

As trxcon+fake_trx don't have GPRS (TBF) support yet, we cannot do
any PCU related tests involving the Um interface yet.  Instead, let's
use virtphy to fill that gap.  Using virtphy, we can actually
receive/transmit GPRS blocks on the simulated Um interface.

TC_pcu_data_req_{pdtch,ptcch} are moved to a new test suite
"BTS_Tests_virtphy.ttcn" which should symbolize that the related tests
are to be executed with osmo-bts-virtual + virtphy instead of
osmo-bts-trx + fake_trx + trxcon.

You also have to set the following module parameter to make this work:
	BTS_Tests.mp_bts_trxc_port := -1

Related: OS#4023
Change-Id: I677f660b1076148b3317b08b06eb3d6551d9b577
1 file changed