Revert "drm/i915: Wait for active retire before i915_active_fini()"

This reverts commit 7a2280e8

, obsoleted
by "drm/i915/vma: Fix UAF on destroy against retire race".

Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Cc: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240305143747.335367-8-janusz.krzysztofik@linux.intel.com