drm/rockchip: vop: Fix reset of state in duplicate state crtc funcs

struct rockchip_crtc_state members such as output_type, output_bpc and
enable_afbc is always reset to zero in the atomic_duplicate_state crtc
funcs.

Fix this by using kmemdup on the subclass rockchip_crtc_state struct.

Fixes: 4e257d9e ("drm/rockchip: get rid of rockchip_drm_crtc_mode_config")
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230621223311.2239547-2-jonas@kwiboo.se

drivers/gpu/drm/rockchip/rockchip_drm_vop.c

@@ -1613,7 +1613,8 @@ static struct drm_crtc_state *vop_crtc_duplicate_state(struct drm_crtc *crtc)
 	if (WARN_ON(!crtc->state))
 		return NULL;
 
-	rockchip_state = kzalloc(sizeof(*rockchip_state), GFP_KERNEL);
+	rockchip_state = kmemdup(to_rockchip_crtc_state(crtc->state),
+				 sizeof(*rockchip_state), GFP_KERNEL);
 	if (!rockchip_state)
 		return NULL;