drm/bridge: move private data to the end of the struct

WHen adding HDMI fields I didn't notice the private: declaration for HPD
fields. Move private fields to the end of the struct drm_bride to have
clear distinction between private and public fields.

Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20250517-drm-hdmi-connector-cec-v6-1-35651db6f19b@oss.qualcomm.com


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>