drm: kirin: Revert "Fix for hikey620 display offset problem"

This reverts commit ff57c651.

With the commit ff57c651 ("drm: kirin: Fix for hikey620
display offset problem") we added support for handling LDI
overflows by resetting the hardware.

However, its been observed that when we do hit the LDI overflow
condition, the irq seems to be screaming, and we do nothing but
stream:
  [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow!
over and over to the screen

I've tried a few appraoches to avoid this, but none has yet
been successful and the cure here is worse then the original
disease, so revert this for now.

Cc: Xinliang Liu <xinliang.liu@linaro.org>
Cc: Rongrong Zou <zourongrong@gmail.com>
Cc: Xinwei Kong <kong.kongxinwei@hisilicon.com>
Cc: Chen Feng <puck.chen@hisilicon.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel <dri-devel@lists.freedesktop.org>
Fixes: ff57c651

 ("drm: kirin: Fix for hikey620 display offset problem")
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Xinliang Liu <xinliang.liu@linaro.org>
Signed-off-by: Xinliang Liu <xinliang.liu@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200303163228.52741-1-john.stultz@linaro.org