drm/i915: Properly write lock bw_state when it changes

The current code also forgets to call intel_atomic_lock_global_state()
when other stuff besides the final min_cdlck changes in the state.
That means we may throw away data which actually has changed, and
thus we can't be at all sure what the code ends up doing during
subsequent commits. Do the write lock properly.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220303191207.27931-8-ville.syrjala@linux.intel.com


Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>