vm_guest_tools: Switch to mesa gbm instead of minigbm.

Xwayland with glamor (required for DRI and virtio-gpu) requires actual
gbm and not just minigbm since there are expectations on actual
structures matching and APIs not implemented with minigbm.

BUG=chromium:837073
TEST=emerge-tatl vm_guest_tools w/o minigbm
CQ-DEPEND=CL:1244069

Change-Id: I58543cd81e59cb79b93cbaa210e21ff15465bf19
Reviewed-on: https://chromium-review.googlesource.com/1244067
Commit-Ready: David Riley <davidriley@chromium.org>
Tested-by: David Riley <davidriley@chromium.org>
Reviewed-by: David Riley <davidriley@chromium.org>
1 file changed