drm/i915/display: Revert "drm/i915/display: Skip C10 state verification in case of fastset"

This reverts commit a1d91c6e

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Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240523134649.31452-2-mika.kahola@intel.com