drm/i915/skl: Update DDI translation tables for SKL

While comparing the B-Spec with the code I noticed that several
values in these tables have been updated in the spec, so I
changed the code to match..

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jim Bride <jim.bride@linux.intel.com>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446852654-883-1-git-send-email-jim.bride@linux.intel.com