The PBDE optimizations aren't supported in all firmware revs.

Make optimizations configurable in case there's a side effect on old
firmware.
Signed-off-by: NDick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>