build: remove unnecessary variable

build: remove unnecessary variable

Since all libraries are explicitly linked as part of a build, we no longer
need to track ones that should be always included for linking against apps.

Previously telemetry was special-cased for linking as it was not directly
needed by the linker when linking the apps, since they never called into it
directly. This meant that it could be forgotten when specifying the app
dependencies, and so the telemetry support would not work. This
special-casing was never needed for make as it always linked in all
libraries, as meson does now.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Luca Boccassi <bluca@debian.org>
Acked-by: Sunil Pai G <sunil.pai.g@intel.com>