[Intel-gfx] [PATCH 4/4] drm/i915: Stop rings before cleaning up on reset

[shuang.he at intel.com]

Tested-By: PRC QA PRTS (Patch Regression Test System Contact: shuang.he at intel.com)
Task id: 5989
-------------------------------------Summary-------------------------------------
Platform          Delta          drm-intel-nightly          Series Applied
PNV                                  268/268              268/268
ILK                                  303/303              303/303
SNB                                  283/283              283/283
IVB                 -1              343/343              342/343
BYT                                  287/287              287/287
HSW                                  363/363              363/363
BDW                                  308/308              308/308
-------------------------------------Detailed-------------------------------------
Platform  Test                                drm-intel-nightly          Series Applied
*IVB  igt_gem_userptr_blits_minor-unsync-normal      PASS(2)      DMESG_WARN(1)PASS(1)
Note: You need to pay more attention to line start with '*'