i965: Make room in the batch epilogue for three more pipe controls.

i965: Make room in the batch epilogue for three more pipe controls.

Review carefully, it sucks to have to keep track of the number of
command packet dwords emitted in the batch epilogue manually.  The
MI_REPORT_PERF_COUNT_BATCH_DWORDS calculation was obviously wrong.

Cc: "12.0 11.1 11.2" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>