drm/i915: KBL - Recommended buffer translation programming for DisplayPort

According to spec: "KBL re-uses SKL values, except where
specific KBL values are listed."

And recently spec has changed adding different table for Display Port only.
But for all SKUs (H,S,U,Y) we have slightly different values.

v2: Fix wrong condition spotted by Jani.
v3: Fix 7th entry of KBL H and S table - by Manasi.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476806256-13318-1-git-send-email-rodrigo.vivi@intel.com