glamor: Set AMDGPU_CREATE_PIXMAP_SCANOUT on DRI2 and shared pixmaps

The scanout usage flag wasn't applied for DRI2 and shared pixmaps
in 0732f81a, resulting in GPU artifacts in some scenarios.

Fixes: 0732f81a ("glamor: Make pixmap scanout compatible if its
                      dimensions are")
Closes: xorg/driver/xf86-video-amdgpu#41
Signed-off-by: Dor Askayo <>
Signed-off-by: Michel Dänzer <>
Reviewed-by: Michel Dänzer <>
12 jobs for fix-dri2-scanout-pixmap in 1 minute and 2 seconds (queued for 8 seconds)