drm/msm/dsi: do not store internal bridge pointer

Since the driver was switched to devm_drm_bridge_add(), there is no need
anymore to store the created bridge instance in struct msm_dsi. Drop
this field and pass data directly.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/561693/
Link: https://lore.kernel.org/r/20231009205727.2781802-2-dmitry.baryshkov@linaro.org