drm/hisilicon/hibmc: Refactor the member of drm_aux in struct hibmc_dp

drm/hisilicon/hibmc: Refactor the member of drm_aux in struct hibmc_dp

Because the drm_aux of struct hibmc_dp_dev's member is not easy to get in
hibmc_drm_dp.c, move the drm_aux to struct hibmc_dp. Then there are some
adaptations and modifications to make this patch compile.

Signed-off-by: Baihan Li <libaihan@huawei.com>
Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20250331074212.3370287-5-shiyongbang@huawei.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>