qxl: add fb and ttm entry points for use by suspend/resume.

This just ports some APIs like radeon uses to provide hooks for s/r to
call.

Signed-off-by: Dave Airlie <airlied@redhat.com>

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

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

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