drm/panel: himax-hx83102: Check for errors on the NOP in prepare()

drm/panel: himax-hx83102: Check for errors on the NOP in prepare()

The mipi_dsi_dcs_nop() function returns an error but we weren't
checking it in hx83102_prepare(). Add a check. This is highly unlikely
to matter in practice. If the NOP failed then likely later MIPI
commands would fail too.

Found by code inspection.

Fixes: 0ef94554dc40 ("drm/panel: himax-hx83102: Break out as separate driver")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240517143643.7.I3fae28745bf2cacd8dac04d7a06daea50e233f46@changeid
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240517143643.7.I3fae28745bf2cacd8dac04d7a06daea50e233f46@changeid