drm/i915: Consolidate TLB invalidation flow

As the logic for selecting the register and corresponsing values grew, the
code become a bit unsightly. Consolidate by storing the required values at
engine init time in the engine itself, and by doing so minimise the amount
of invariant platform and engine checks during each and every TLB
invalidation.

v2:
 * Fail engine probe if TLB invlidations registers are unknown.

v3:
 * Rebase.

v4:
 * Fix handling of GEN8_M2TCR. (Andrzej)

v5:
 * Tidy checkpatch warnings.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com> # v1
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230216092123.159085-1-tvrtko.ursulin@linux.intel.com