dbtools were added in 01089138 only to
create dependency and fix the build.
This creates circular dependency for libmerged, dbtools is not that
common library.
It's better to create real dependency in connectivity_inc package.
To avoid another circular dependency gb_YaccTarget_get_header_target
must not depend on external headers target.

Change-Id: I536376303de5330addd2dbf85bdfea8b9a23301c