drm/i915/dg2: Add additional HDMI pixel clock frequencies

Using the BSPEC algorithm add addition HDMI pixel clocks to the existing
table.

Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Signed-off-by: Taylor, Clinton A <clinton.a.taylor@intel.com>