MIPS: Octeon: Remove vestiges of CONFIG_CAVIUM_RESERVE32_USE_WIRED_TLB

The config option CAVIUM_RESERVE32_USE_WIRED_TLB is not supported.
Remove the dead code controlled by it.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1028/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>