drm/i915/debugfs: Drop i915_hws_info

drm/i915/debugfs: Drop i915_hws_info

i915_hws_info() has not been kept upto date (missing new engines) and so
I consider it to be unused. HWS is included in the error state, which
would be an avenue to retrieving it if required in future (possibly via
i915_engine_info). As it is currently oopsing with an rpm testcase, just
remove it.

Fixes: 3b3f1650b1ca ("drm/i915: Allocate intel_engine_cs structure only for the enabled engines")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98838
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161124093401.18852-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>