drm/i915: Add missing tab to DRRS debugfs

The DRRS refresh rate should be indented by one tab like the
other per-crtc DRRS stuff.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220315132752.11849-3-ville.syrjala@linux.intel.com


Reviewed-by: José Roberto de Souza <jose.souza@intel.com>