drm/msm/dsi: print error code when MIPI DSI host registration fails

In order to ease debugging of DSI host registration issues, print return
code of dsi_mgr_setup_components().

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>