drm/rockchip: vop2: Fix interface enable/mux setting of DP1 on rk3588

This is a copy-paste error, which affects DP1 usage.

Fixes: 328e6885 ("drm/rockchip: vop2: Add platform specific callback")
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20250312064218.524143-1-andyshrk@163.com