minigbm: add MINIGBM define.

This patch does not bring any functionality changes, but just
adds a MINIGBM define in order to be able to distiguish if
Chromium, for example, uses a system libgbm (needed by Ozone/Wayland
builds for Linux due to some diffirences, which we cannot fix yet)
or minigbm.

Change-Id: I82366ce9a1c302124b75a6c21028a67127497065
Reviewed-on: https://chromium-review.googlesource.com/1281887
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Maksim Sisov <msisov@igalia.com>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
1 file changed