Revert "[sys-kernel/e-sources]: Disabled BFQ."

This reverts commit 368ab875f3c98be0a7b7c01b3890cb6fb657f7c0.
Revert "[sys-kernel/e-sources]: Version bump to 3.9.7"

This reverts commit 9ce78de12db48cf37fb57f672471e4c511537407.