drm/i915: Fix up the bdw pipe interrupt enable lists

- Pipe underrun can't just be enabled, we need some support code like
  on ilk-hsw to make this happen. So drop it for now.
- CRC error is a special mode of the CRC hardware that we don't use,
  so again drop it. Real CRC support for bdw will be added later.
- All the other error bits are about faults, so rename the #define and
  adjust the output.

v2: Use pipe_name as pointed out by Ville. Ville's comment was on a
previous patch, but it was easier to squash in here.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>