drm/i915: Expose logical engine instance to user

Expose logical engine instance to user via query engine info IOCTL. This
is required for split-frame workloads as these needs to be placed on
engines in a logically contiguous order. The logical mapping can change
based on fusing. Rather than having user have knowledge of the fusing we
simply just expose the logical mapping with the existing query engine
info IOCTL.

IGT: https://patchwork.freedesktop.org/patch/445637/?series=92854&rev=1
media UMD: https://github.com/intel/media-driver/pull/1252



v2:
 (Daniel Vetter)
  - Add IGT link, placeholder for media UMD

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014172005.27155-7-matthew.brost@intel.com