MIPS: Set up FTLB probability for I6400

Set up the I6400 FTLB probability similar to P5600 and proAptiv.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10652/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>