drm: kirin: Revert change to add register connect helper functions

drm: kirin: Revert change to add register connect helper functions

Daniel noted[1] that commit d606dc9a6323 ("drm: kirin: Add
register connect helper functions in drm init") was unnecessary
and incorrect, as drm_dev_register does register connectors for
us.

Thus, this patch reverts the change as suggested by Daniel.

[1]: https://lore.kernel.org/lkml/CAKMK7uHr5U-pPsxdQ4MpfK5v8iLjphDFug_3VTiUAf06nhS=yQ@mail.gmail.com/

Cc: Xu YiPing <xuyiping@hisilicon.com>
Cc: Rongrong Zou <zourongrong@gmail.com>
Cc: Xinliang Liu <xinliang.liu@linaro.org>
Cc: Xinwei Kong <kong.kongxinwei@hisilicon.com>
Cc: Chen Feng <puck.chen@hisilicon.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: dri-devel <dri-devel@lists.freedesktop.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Xinliang Liu <xinliang.liu@linaro.org>
Signed-off-by: Xinliang Liu <xinliang.liu@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200409004306.18541-1-john.stultz@linaro.org