minigbm: use drv_add_combination when adding a single combination

We defined the function, but it's since gone unused.

Change-Id: I23e7e57413c4a7c82d9da302b79e6b9c5068654d
Reviewed-on: https://chromium-review.googlesource.com/1229438
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