drm/i915/skl: Add back HDMI translation table

The HDMI translation table is added back to bspec, so adding it,
and defaulting the 800mV+0dB entry.

The HDMI translation table was removed by following commit as per HW team's
recommendation:
commit 7ff44670 ("drm/i915/skl: Only use the 800mV+2bB HDMI translation entry")

v2: Adding reference to commit which removed this table (Jani)

Cc: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Sonika Jindal <sonika.jindal@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>