drm/qxl: simple crtc page flipping emulated using buffer copy

Signed-off-by: Andreas Pokorny <andreas.pokorny@canonical.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --cc drivers/gpu/drm/qxl/qxl_display.c
Simple merge

diff --cc drivers/gpu/drm/qxl/qxl_drv.c
Simple merge

diff --cc drivers/gpu/drm/qxl/qxl_kms.c
Simple merge