qat: Revert changes to BAR indices

It is not clear how commit ded037e65e52 could reasonably change BAR
indices, and doing so broke at least the C3000 driver. Revert that part
of the change.

Reported by: kp
Reviewed by: kp, Haresh Sankar Raj <hareshx.sankar.raj@intel.com>
MFC after: 3 days
Fixes: ded037e65e52 ("qat: driver updates to improve code and fix bugs")
Differential Revision: https://reviews.freebsd.org/D51664

(cherry picked from commit 4a8e62a1209f7d7529817c4c27b91fb97750b7b2)