Add revisionID to GpuDeviceInfo and populate it through libpci.

Bug: b/170372516
Change-Id: I0953ba5dfc7d973c7b7216d942952a3ffd908bcb
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2703734Reviewed-by: Jonah Ryan-Davis <jonahr@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>