Add virglrenderer to QEMU.

This enables to use launch_cvd --gpu_mode=drm_virgl.

libgbm.so is used from the system as it is made available
by mesa which is a large project that would be difficult
to add to AOSP.

Bug: b/309616187
Change-Id: I6126b041dbf9bff9dfbd3c5a179f144a6babb54d
4 files changed