drm/i915: Fail if DSC compression requirement is less than platform supports

drm/i915: Fail if DSC compression requirement is less than platform supports

Currently we just clamp that value to the highest supported one, however that
means, we are not able to fit this into our available bandwidth range, so we
might see glitches or FIFO underruns.
While choosing less compressed bpp than min bpp required to handle the mode is
harmless and might even save some bandwidth, choosing higher compressed bpp than
min bpp required to handle the required mode config, can cause issues.
So in that case lets just conclude that even with DSC, we are not able to comply
with bandwidth requirements and fail.

v2: - s/clamp_t/min_t/ (Luca Coelho)

Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230629122534.8815-1-stanislav.lisovskiy@intel.com