drm/i915: Use correct fw_domains during reset

In the next patch we will begin to sanity check that we do not attempt
to obtain the forcewake on an unsupport domain. However, that is exactly
what we do during reset of the fw_domains - rectify it before it explodes.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170323101944.21627-3-chris@chris-wilson.co.uk