drm/panel: boe-tv101wum-nl6: restore MODE_LPM after sending disable cmds

drm/panel: boe-tv101wum-nl6: restore MODE_LPM after sending disable cmds

When preparing the panel, it seems that it always expects commands to be
transferred in LP mode. However, the disable function removes the
MIPI_DSI_MODE_LPM flag, and no other function re-adds it.

As the unprepare function contains no DSI commands, re-adding the flag
just after disabling the panel should be safe. Add the code re-adding
the flag after the two commands for disabling the panel are sent.

This fixes error messages shown in kernel log when unblanking on
mt8183-kukui-kodama-sku32 device.

Cc: stable@vger.kernel.org
Fixes: a869b9db7adf ("drm/panel: support for boe tv101wum-nl6 wuxga dsi video mode panel")
Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260503091708.1079962-1-zhengxingda@iscas.ac.cn