Many of the DDI buffer translation values have changed for BDW.
Add new translation tables and selection between HSW and BDW.
v2: s/BUG/WARN/ to avoid breaking future GENs.
v3: Rebase on top of the hdmi translation table changes.
v4: Fix up the multiline comment while at it.
Signed-off-by: Art Runyan <arthur.j.runyan@intel.com> (v2) Reviewed-by: Ben Widawsky <ben@bwidawsk.net> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>