minigbm: Enable vc4 driver

BUG=None
TEST=graphics_Gbm on target board

Change-Id: Id92466354e644f9237f8c19aebd0534c1b23bbc0
Reviewed-on: https://chromium-review.googlesource.com/989301
Commit-Ready: Jeremy Grosser <jeremy@synack.me>
Tested-by: Jeremy Grosser <jeremy@synack.me>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
2 files changed