drm/bridge: lvds-codec: Implement atomic_get_input_bus_fmts for LVDS encoder

atomic_get_input_bus_fmts is only implemented for LVDS decoders, resulting
that LVDS encoders only support bus format MEDIA_BUS_FMT_FIXED. This
results in warnings like:
mxsfb 21c8000.lcdif: Bridge does not provide bus format, assuming
 MEDIA_BUS_FMT_RGB888_1X24.
Please fix bridge driver by handling atomic_get_input_bus_fmts.

Fix this by reusing lvds_codec_atomic_get_input_bus_fmts currently used
for LVDS decoders. Use RGB888_1X24 for LVDS encoders. This also allows
removing the dedicated struct drm_bridge_funcs for decoders.
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230810063229.597533-1-alexander.stein@ew.tq-group.com

drivers/gpu/drm/bridge/lvds-codec.c

@@ -5,6 +5,7 @@
  */
 
 #include <linux/gpio/consumer.h>
+#include <linux/media-bus-format.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_graph.h>
@@ -71,12 +72,6 @@ static void lvds_codec_disable(struct drm_bridge *bridge)
 			"Failed to disable regulator \"vcc\": %d\n", ret);
 }
 
-static const struct drm_bridge_funcs funcs = {
-	.attach = lvds_codec_attach,
-	.enable = lvds_codec_enable,
-	.disable = lvds_codec_disable,
-};
-
 #define MAX_INPUT_SEL_FORMATS 1
 static u32 *
 lvds_codec_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
@@ -102,7 +97,7 @@ lvds_codec_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
 	return input_fmts;
 }
 
-static const struct drm_bridge_funcs funcs_decoder = {
+static const struct drm_bridge_funcs funcs = {
 	.attach = lvds_codec_attach,
 	.enable = lvds_codec_enable,
 	.disable = lvds_codec_disable,
@@ -184,8 +179,9 @@ static int lvds_codec_probe(struct platform_device *pdev)
 			return ret;
 		} else {
 			lvds_codec->bus_format = ret;
-			lvds_codec->bridge.funcs = &funcs_decoder;
 		}
+	} else {
+		lvds_codec->bus_format = MEDIA_BUS_FMT_RGB888_1X24;
 	}
 
 	/*