[Intel-gfx] [PATCH v2] drm/i915/bdw: Enable execlists by default where supported

[shuang.he at intel.com]

Tested-By: PRC QA PRTS (Patch Regression Test System Contact: shuang.he at intel.com)
-------------------------------------Summary-------------------------------------
Platform          Delta          drm-intel-nightly          Series Applied
PNV                                  364/364              364/364
ILK              +1                 364/366              365/366
SNB                                  448/450              448/450
IVB                                  497/498              497/498
BYT                                  289/289              289/289
HSW                 -1              563/564              562/564
BDW                                  417/417              417/417
-------------------------------------Detailed-------------------------------------
Platform  Test                                drm-intel-nightly          Series Applied
 ILK  igt_kms_flip_wf_vblank-ts-check      DMESG_WARN(7, M26)PASS(25, M26M37)      PASS(1, M37)
*HSW  igt_pm_rpm_dpms-mode-unset-non-lpsp      PASS(3, M40)      DMESG_WARN(1, M40)
Note: You need to pay more attention to line start with '*'