[Intel-gfx] [PATCH] drm/i915/skl: revert duplicated WaBarrierPerformanceFixDisable:skl

[shuang.he at intel.com]

Tested-By: Intel Graphics QA PRTS (Patch Regression Test System Contact: shuang.he at intel.com)
Task id: 6895
-------------------------------------Summary-------------------------------------
Platform          Delta          drm-intel-nightly          Series Applied
ILK                 -1              297/297              296/297
SNB                                  315/315              315/315
IVB                                  342/342              342/342
BYT                 -1              282/282              281/282
HSW                                  378/378              378/378
-------------------------------------Detailed-------------------------------------
Platform  Test                                drm-intel-nightly          Series Applied
*ILK  igt at kms_flip@flip-vs-dpms-interruptible      PASS(1)      DMESG_WARN(1)
*BYT  igt at gem_tiled_partial_pwrite_pread@reads      PASS(1)      FAIL(1)
Note: You need to pay more attention to line start with '*'