drm/i915/tgl: Update cdclk voltage level settings

A recent bspec update added an extra voltage level that we didn't have
on ICL and new criteria for selecting the level.

Bspec: 49208
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200207001417.1229251-2-matthew.d.roper@intel.com


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