drm/i915: reindent Haswell register definitions

It's the only part of the i915_reg.h file that looks totally wrongly
indented, so I assume my editor config is the correct one.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>