drm: kirin: Move workqueue to ade_hw_ctx structure

The workqueue used to reset the display when we hit an LDI
underflow error is ADE specific, so since this patch series
works to make the kirin_crtc structure more generic, move the
workqueue to the ade_hw_ctx structure instead.

Cc: Rongrong Zou <zourongrong@gmail.com>
Cc: Xinliang Liu <z.liuxinliang@hisilicon.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel <dri-devel@lists.freedesktop.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Xinliang Liu <z.liuxinliang@hisilicon.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190820230626.23253-11-john.stultz@linaro.org