drm/exynos: exynos_dp: Remove &exynos_dp_device.ptn_bridge

drm/exynos: exynos_dp: Remove &exynos_dp_device.ptn_bridge

Use &analogix_dp_plat_data.bridge instead of &exynos_dp_device.ptn_bridge
directly.

Signed-off-by: Damon Ding <damon.ding@rock-chips.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Heiko Stuebner <heiko@sntech.de> # rk3588
Link: https://patch.msgid.link/20260409065301.446670-4-damon.ding@rock-chips.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>