drm/tidss: Fix missing includes and struct decls

Fix missing includes and struct declarations. Even if these don't cause
any compile issues at the moment, it's good to have them correct.

Reviewed-by: Aradhya Bhatia <aradhya.bhatia@linux.dev>
Tested-by: Parth Pancholi <parth.pancholi@toradex.com>
Tested-by: Jayesh Choudhary <j-choudhary@ti.com>
Reviewed-by: Devarsh Thakkar <devarsht@ti.com>
Link: https://lore.kernel.org/r/20250723-cdns-dsi-impro-v5-2-e61cc06074c2@ideasonboard.com
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

drivers/gpu/drm/tidss/tidss_dispc.h

@@ -7,11 +7,14 @@
 #ifndef __TIDSS_DISPC_H__
 #define __TIDSS_DISPC_H__
 
+#include <drm/drm_color_mgmt.h>
+
 #include "tidss_drv.h"
 
 struct dispc_device;
 
 struct drm_crtc_state;
+struct drm_plane_state;
 
 enum tidss_gamma_type { TIDSS_GAMMA_8BIT, TIDSS_GAMMA_10BIT };
 

drivers/gpu/drm/tidss/tidss_drv.h

@@ -9,6 +9,8 @@
 
 #include <linux/spinlock.h>
 
+#include <drm/drm_device.h>
+
 #define TIDSS_MAX_PORTS 4
 #define TIDSS_MAX_PLANES 4
 #define TIDSS_MAX_OLDI_TXES 2

drivers/gpu/drm/tidss/tidss_plane.h

@@ -7,6 +7,8 @@
 #ifndef __TIDSS_PLANE_H__
 #define __TIDSS_PLANE_H__
 
+#include <drm/drm_plane.h>
+
 #define to_tidss_plane(p) container_of((p), struct tidss_plane, plane)
 
 struct tidss_device;

drivers/gpu/drm/tidss/tidss_scale_coefs.h

@@ -9,6 +9,8 @@
 
 #include <linux/types.h>
 
+struct device;
+
 struct tidss_scale_coefs {
 	s16 c2[16];
 	s16 c1[16];