cwm: Declare additional dependencies instead of relying on build hax

We want to include a suite of tools and symlinks with recovery.  This
was previously done with a hack in build/core/Makefile.  That is rather
unorthodox.  Instead, use LOCAL_ADDITIONAL_DEPENDENCIES to declare the
things we want to include.

See also http://review.cyanogenmod.org/74244

Change-Id: Ib054f2bc8aa85cb3df9cbeba3f457ea74dd3ed98