RDMA/cxgb4: Only allow kernel db ringing for T4 devs
RDMA/cxgb4: Only allow kernel db ringing for T4 devs

The whole db drop avoidance stuff is for T4 only.  So we cannot allow
that to be enabled for T5 devices.

Signed-off-by: Steve Wise <6f43c86433b33e5fe92b209bedebd0f6dba5b49c@opengridcomputing.com>
Signed-off-by: Roland Dreier <0d270388f2f92757a5de0f4bd891d3b392c44c4f@purestorage.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs