drm/rockchip: remove unused struct in vop2

These structs are undefined and un used.

Fixes: 604be855 ("drm/rockchip: Add VOP2 driver")
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20231013122036.1594090-1-andyshrk@163.com