deprecate 'msc' / 'ip.access rtp-base <port>'

The bsc_msc_data->rtp_base has been unused ever since we introduced the exernal
MGW in osmo-bsc [1]. The vty command also still exists. Deprecate the vty
command, remove the member.

[1] "mgcp: use osmo-mgw to switch RTP streams"
    commit 39c609b7c924524172ad311bdf89f92b7ccf175a
    Change-Id Ia2882b7ca31a3219c676986e85045fa08a425d7a

Change-Id: Id14fa3066ca5d472a817593074a6222f159168a8
4 files changed