Revert "Ozone DRM: use GBM_BO_USE_HW_VIDEO_DECODER"

This reverts commit 398ca322.

Reason for revert: Breaks protected content playback in ARM platform.

Original change's description:
> Ozone DRM: use GBM_BO_USE_HW_VIDEO_DECODER
> 
> This CL adds the GBM_BO_USE_HW_VIDEO_DECODER flag to
> gfx::BufferUsage::SCANOUT_VDA_WRITE buffers. It's a spinoff of a
> comment [1] in crrev.com/c/1021675.
> 
> [1] https://chromium-review.googlesource.com/c/chromium/src/+/1021675/18/ui/ozone/platform/drm/gpu/drm_thread.cc#147
> 
> Bug: 822346
> Test: simplechrome video playback on nautilus, vaapi engaged.
> Change-Id: I795c6c3f74574ffab60c24d1ef746b22d214120a
> Reviewed-on: https://chromium-review.googlesource.com/1104394
> Reviewed-by: Daniele Castagna <dcastagna@chromium.org>
> Commit-Queue: Miguel Casas <mcasas@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#568027}

TBR=mcasas@chromium.org,dcastagna@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 822346
Change-Id: I8b9af48859886f0ef9c203a06079dadd53f0e477
Reviewed-on: https://chromium-review.googlesource.com/1116738Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Commit-Queue: Hirokazu Honda <hiroh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570720}

ui/ozone/platform/drm/gpu/drm_thread.cc

@@ -145,8 +145,7 @@ void DrmThread::CreateBuffer(gfx::AcceleratedWidget widget,
       flags = GBM_BO_USE_LINEAR | GBM_BO_USE_SCANOUT | GBM_BO_USE_TEXTURING;
       break;
     case gfx::BufferUsage::SCANOUT_VDA_WRITE:
-      flags = GBM_BO_USE_SCANOUT | GBM_BO_USE_TEXTURING |
-              GBM_BO_USE_HW_VIDEO_DECODER;
+      flags = GBM_BO_USE_SCANOUT | GBM_BO_USE_TEXTURING;
       break;
     case gfx::BufferUsage::GPU_READ_CPU_READ_WRITE:
     case gfx::BufferUsage::GPU_READ_CPU_READ_WRITE_PERSISTENT: