sdk: Add missing libosmotrau-dev after split from libosmo-abis

After splitting libosmotrau from libosmo-abis in
127bed3ceb41015d8fd36779689ab6d799f773f6, related libosmotrau dev were
moved to its own package, which was not added to the include list for
the SDK. As a result, somo-bts cannot be built anymore as it fails to
find libosmotrau pkgconfig file, headers and shared object file.

Change-Id: I42f3fa2ad82bfadb48f22167e42a08974fef16ab
2 files changed