drm/i915: Restore relaxed padding (OCL_OOB_SUPPRES_ENABLE) for skl+

This bit was fliped on for "syncing dependencies between camera and
graphics". BSpec has no recollection why, and it is causing
unrecoverable GPU hangs with Vulkan compute workloads.

From BSpec, setting bit5 to 0 enables relaxed padding requirements for
buffers, 1D and 2D non-array, non-MSAA, non-mip-mapped linear surfaces;
and *must* be set to 0h on skl+ to ensure "Out of Bounds" case is
suppressed.

Reported-by: Jason Ekstrand <jason@jlekstrand.net>
Suggested-by: Jason Ekstrand <jason@jlekstrand.net>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110998
Fixes: 8424171 ("drm/i915/gen9: h/w w/a: syncing dependencies between camera and graphics")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: denys.kostin@globallogic.com
Cc: Jason Ekstrand <jason@jlekstrand.net>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.1+
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190904100707.7377-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/intel_workarounds.c

@@ -297,11 +297,6 @@ static void gen9_ctx_workarounds_init(struct intel_engine_cs *engine,
  FLOW_CONTROL_ENABLE |
  PARTIAL_INSTRUCTION_SHOOTDOWN_DISABLE);
 
- /* Syncing dependencies between camera and graphics:skl,bxt,kbl */
- if (!IS_COFFEELAKE(i915))
- WA_SET_BIT_MASKED(HALF_SLICE_CHICKEN3,
- GEN9_DISABLE_OCL_OOB_SUPPRESS_LOGIC);
-
  /* WaEnableYV12BugFixInHalfSliceChicken7:skl,bxt,kbl,glk,cfl */
  /* WaEnableSamplerGPGPUPreemptionSupport:skl,bxt,kbl,cfl */
  WA_SET_BIT_MASKED(GEN9_HALF_SLICE_CHICKEN7,