convert drm_atomic_helper_suspend/resume() to use
drm_mode_config_helper_suspend/resume().

Fixed one sparse warning by making hibmc_drm_interrupt
static.
Signed-off-by: NAjit Negi <ajitn.linux@gmail.com>
Signed-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: NXinliang Liu <z.liuxinliang@hisilicon.com>
Signed-off-by: NXinliang Liu <z.liuxinliang@hisilicon.com>