drm/bridge: parade-ps8640: remove unused drm_panel.h include

The file uses the panel_bridge APIs from drm_bridge.h, but no drm_panel
APIs from drm_panel.h.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250206-drm-cleanups-v1-4-93df60faa756@bootlin.com

Author: lucaceresoli

drivers/gpu/drm/bridge/parade-ps8640.c

@@ -20,7 +20,6 @@
 #include <drm/drm_edid.h>
 #include <drm/drm_mipi_dsi.h>
 #include <drm/drm_of.h>
-#include <drm/drm_panel.h>
 #include <drm/drm_print.h>
 
 #define PAGE0_AUXCH_CFG3	0x76