drm/rockchip: vop2: Support for different layer select configuration between VPs

In the upcoming VOP for rk3576, every VP has it's own LAYER_SEL
register, and the configuration value of each VP for the same
window maybe different, so extend the layer_sel_id to array,
let it can descption the layer select configuration value for
different VP.

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Tested-by: Michael Riesch <michael.riesch@wolfvision.net> # on RK3568
Tested-by: Detlev Casanova <detlev.casanova@collabora.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20250218112744.34433-6-andyshrk@163.com