[Intel-gfx] [PATCH v2] drm/i915: Reject modeset when the same digital port is used more than once

[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                 -1              364/364              363/364
ILK              +1                 365/366              366/366
SNB                                  450/450              450/450
IVB                                  498/498              498/498
BYT                                  289/289              289/289
HSW                 -1              564/564              563/564
BDW                                  417/417              417/417
-------------------------------------Detailed-------------------------------------
Platform  Test                                drm-intel-nightly          Series Applied
*PNV  igt_gem_partial_pwrite_pread_write      PASS(2, M25M7)      NO_RESULT(1, M7)
 ILK  igt_kms_flip_wf_vblank-ts-check      DMESG_WARN(2, M26)PASS(10, M26M37)      PASS(1, M37)
*HSW  igt_gem_flink_race_flink_close      PASS(2, M19)      DMESG_WARN(1, M19)
Note: You need to pay more attention to line start with '*'