drm/panel: jdi-lt070me05000: Use MIPI DSI multi functions

drm/panel: jdi-lt070me05000: Use MIPI DSI multi functions

Convert to the non-deprecated mipi_dsi_*_multi() helpers per the TODO
list. This reduces boilerplate error checking while providing proper
error accumulation.

Use mipi_dsi_msleep() and mipi_dsi_usleep_range() macros for delays.
Replace mdelay(10) and mdelay(20) with mipi_dsi_usleep_range() calls
using tighter slop (10-11ms and 20-21ms respectively) since these
functions aren't run often and don't need large timing windows.

In jdi_panel_off(), reset the error context between display_off and
enter_sleep_mode to preserve the original behavior of continuing power-down
even if display_off fails. This ensures enter_sleep_mode executes before
GPIO/regulator control, which is critical for proper power sequencing.

Signed-off-by: Chintan Patel <chintanlike@gmail.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patch.msgid.link/20260203044605.5890-1-chintanlike@gmail.com