Revert "block: Switch from BFQ-v7r2 for 3.13.0 to BFQ-v7r3 for 3.13.0"

This reverts commit 5a091d397d9403d2b3d6421892354b3d644f92ac.

Causes a kernel panic immediately on boot.  Reverting for now.
Merge branch '3.13/bfq' into 3.13/master