MIPS: Add support for NXP PNX833x (STB222/5) into linux kernel

The following patch add support for the NXP PNX833x SOC.  More
specifically it adds support for the STB222/5 variant. It fixes
the vectored interrupt issue.

Signed-off-by: daniel.j.laird <daniel.j.laird@nxp.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>