minigbm: delete unused functions and definitions

Change-Id: Ie5f8b148e3f051edde08b0b46ab22a80f034ff80
Reviewed-on: https://chromium-review.googlesource.com/1229437
Commit-Ready: Gurchetan Singh <gurchetansingh@chromium.org>
Tested-by: Gurchetan Singh <gurchetansingh@chromium.org>
Reviewed-by: St├ęphane Marchesin <marcheu@chromium.org>
3 files changed