drm/i915: Add some L3 registers to the parser whitelist

Beignet needs these in order to program the L3 cache config for
OpenCL workloads, particularly when using SLM.

Signed-off-by: Brad Volkin <bradley.d.volkin@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
index 9d79543..dea99d9 100644
--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -426,6 +426,9 @@
 	GEN7_SO_WRITE_OFFSET(1),
 	GEN7_SO_WRITE_OFFSET(2),
 	GEN7_SO_WRITE_OFFSET(3),
+	GEN7_L3SQCREG1,
+	GEN7_L3CNTLREG2,
+	GEN7_L3CNTLREG3,
 };
 
 static const u32 gen7_blt_regs[] = {