drm/msm/dsi: fix initialization in the bonded DSI case

Commit 739b4e77 ("drm/msm/dsi: Fix an error code in
msm_dsi_modeset_init()") changed msm_dsi_modeset_init() to return an
error code in case msm_dsi_manager_validate_current_config() returns
false. However this is not an error case, but a slave DSI of the bonded
DSI link. In this case msm_dsi_modeset_init() should return 0, but just
skip connector and bridge initialization.

To reduce possible confusion, drop the
msm_dsi_manager_validate_current_config() function, and specif 'bonded
&& !master' condition directly in the msm_dsi_modeset_init().

Fixes: 739b4e77

 ("drm/msm/dsi: Fix an error code in msm_dsi_modeset_init()")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Link: https://lore.kernel.org/r/20211125180114.561278-1-dmitry.baryshkov@linaro.org
Signed-off-by: Rob Clark <robdclark@chromium.org>