MIPS: Use BBIT instructions in TLB handlers

If the CPU supports BBIT0 and BBIT1, use them in TLB handlers as they
are more efficient than an AND followed by an branch and then
restoring the clobbered register.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1873/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>