drm/sun4i: hdmi: Switch to container_of_const

container_of_const() allows to preserve the pointer constness and is
thus more flexible than inline functions.

Let's switch all our instances of container_of() to container_of_const().
Reviewed-by: Sui Jingfeng <sui.jingfeng@linux.dev>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240222-kms-hdmi-connector-state-v7-34-8f4af575fce2@kernel.org

drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c

@@ -30,19 +30,11 @@
 #include "sun4i_drv.h"
 #include "sun4i_hdmi.h"
 
-static inline struct sun4i_hdmi *
-drm_encoder_to_sun4i_hdmi(struct drm_encoder *encoder)
-{
-	return container_of(encoder, struct sun4i_hdmi,
-			    encoder);
-}
+#define drm_encoder_to_sun4i_hdmi(e)		\
+	container_of_const(e, struct sun4i_hdmi, encoder)
 
-static inline struct sun4i_hdmi *
-drm_connector_to_sun4i_hdmi(struct drm_connector *connector)
-{
-	return container_of(connector, struct sun4i_hdmi,
-			    connector);
-}
+#define drm_connector_to_sun4i_hdmi(c)		\
+	container_of_const(c, struct sun4i_hdmi, connector)
 
 static int sun4i_hdmi_setup_avi_infoframes(struct sun4i_hdmi *hdmi,
 					   struct drm_display_mode *mode)