drm/rockchip: vop2: don't check color_mgmt_changed in atomic_enable

drm/rockchip: vop2: don't check color_mgmt_changed in atomic_enable

Remove color_mgmt_changed check from vop2_crtc_atomic_try_set_gamma to
allow gamma LUT rewrite during modeset when coming out of suspend. Add
a check for color_mgmt_changed directly in vop2_crtc_atomic_flush.

This patch fixes the patch adding gamma LUT support for vop2 [1].

[1] https://lore.kernel.org/linux-rockchip/20241101185545.559090-3-pZ010001011111@proton.me/

Suggested-by: Andy Yan <andy.yan@rock-chips.com>
Signed-off-by: Piotr Zalewski <pZ010001011111@proton.me>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20241206192013.342692-3-pZ010001011111@proton.me