vndk-def: Remove obsolete warning options

This commit removes `--warn-high-level-ndk-deps` and
`--warn-banned-vendor-lib-deps`.  These options are removed in favor of
the eligible vndk list.  In next CL, a user can specify an eligible VNDK
list with `--tag-file`. VNDK definition tool will print warnings if
vendor modules are using ineligible framework libraries.

Test: ./tests/run.py
Change-Id: I0bb11de70c93f1447bb041561e80e342aa400fd4