drm/panel: Kconfig: Fix spelling mistake "pannel" -> "panel"

There is a spelling mistake in the LEDS_BD2606MVV config. Fix it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250724112358.142351-1-colin.i.king@gmail.com