D3D: Fix RGB5_A1 texture upload from PBO failure on Windows 10 Failure is consistently seen in the dEQP tests on Windows 10 on NVIDIA and Intel drivers, where creating an SRV from the buffer in the right format fails. Disable the fast copy path for this format similarly to how it's already disabled for some other formats. BUG=angleproject:1095 TEST=dEQP-GLES3.functional.texture.specification.teximage2d_pbo.rgb5* Change-Id: I7a1cd15c2cd130c9e8a637457c201778f157333b Reviewed-on: https://chromium-review.googlesource.com/341170 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>