drm/i915: Extract lrr_params_changed()

Pull the "do we actually need a LRR update?" checks into a small
helper for clarity.

Cc: Paz Zcharya <pazz@chromium.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250116201637.22486-6-ville.syrjala@linux.intel.com


Reviewed-by: Jani Nikula <jani.nikula@intel.com>