This reverts commit 7d82d293.

Reason for revert: Suspect CL failing on Linux FYI Ozone

Original change's description:
> Refactor DisplayGbm::generateConfigs
>
> Bug: angleproject:4809
> Change-Id: I5f352f737bbd53c78d9e01055c17eabd17d5fb8a
> Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2278667
> Reviewed-by: Jamie Madill <jmadill@chromium.org>
> Reviewed-by: Geoff Lang <geofflang@chromium.org>
> Commit-Queue: Jiajia Qin <jiajia.qin@intel.com>

TBR=geofflang@chromium.org,jiajia.qin@intel.com,jmadill@chromium.org

Change-Id: I62c8a6a78d1ccfe8aa63bea7a9409229cd0059ab
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: angleproject:4809, chromium:1105208
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2296041
Commit-Queue: Austin Eng <enga@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>