[Intel-gfx] [PATCH] drm/i915: Remove unused workaround bb code and unused struct members

[Chris Wilson]

Quoting Tvrtko Ursulin (2018-01-10 12:24:49)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> After recent code changes this part of the code now looks over-engineered
> and can be simplified, together with the corresponding struct members.

I don't mind, but I was keeping it around just in case we ever need to
re-instantiate a per-bb wa batch.

If the consensus is we won't need one for the foreseeable future,
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris