drm/i915/guc: Remove hacks for reset and schedule disable G2H being received out of order

In the i915 there are several hacks in place to make request cancellation
work with an old version of the GuC which delivered the G2H indicating
schedule disable is done before G2H indicating a context reset. Version
69 fixes this, so we can remove these hacks.

v2:
 (Checkpatch)
  - s/cancelation/cancellation

Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220113181351.21296-3-matthew.brost@intel.com