drm/panel: otm8009a: Set backlight parent to panel device

stable inclusion
from stable-v5.10.180
commit c85327c1e93ceef2bef9bb2d367e8d2b08b88a62
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8FC2O

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c85327c1e93ceef2bef9bb2d367e8d2b08b88a62



--------------------------------

commit ab4f869f upstream.

This is the logical place to put the backlight device, and it also
fixes a kernel crash if the MIPI host is removed. Previously the
backlight device would be unregistered twice when this happened - once
as a child of the MIPI host through `mipi_dsi_host_unregister`, and
once when the panel device is destroyed.

Fixes: 12a6cbd4 ("drm/panel: otm8009a: Use new backlight API")
Signed-off-by: James Cowgill <james.cowgill@blaize.com>
Cc: stable@vger.kernel.org
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230412173450.199592-1-james.cowgill@blaize.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>