drm/panel-elida-kd35t133: hold panel in reset for unprepare

[ Upstream commit 03c5b2a5 ]

For devices like the Anbernic RG351M and RG351P the panel is wired to
an always on regulator. When the device suspends and wakes up, there
are some slight artifacts on the screen that go away over time. If
instead we hold the panel in reset status after it is unprepared,
this does not happen.

Fixes: 5b660336 ("drm/panel: add panel driver for Elida KD35T133 panels")
Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Link: https://lore.kernel.org/r/20231117194405.1386265-3-macroalpha82@gmail.com


Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231117194405.1386265-3-macroalpha82@gmail.com


Signed-off-by: Sasha Levin <sashal@kernel.org>