drm/i915: Do forcewake reset on gen8
drm/i915: Do forcewake reset on gen8

When we get control from BIOS there might be mt forcewake
bits already set. This causes us to do double mt get
without proper clear/ack sequence.

Fix this by clearing mt forcewake register on init,
like we do with older gens.

Signed-off-by: Mika Kuoppala <cd221c71e765d1ce593d15b204fee351fb09fd98@intel.com>
Reviewed-by: Ben Widawsky <73675debcd8a436be48ec22211dcf44fe0df0a64@bwidawsk.net>
Signed-off-by: Daniel Vetter <c1b6782c4af8f0673da8923a0702a1832e5940f4@ffwll.ch>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs