MIPS: Add cacheinfo support

Add cacheinfo support for MIPS architectures.

Use information from the cpuinfo_mips struct to populate the
cacheinfo struct. This allows an architecture agnostic approach,
however this also means if cache information is not properly
populated within the cpuinfo_mips struct, there is nothing
we can do. (I.E. c-r3k.c)

Signed-off-by: Justin Chen <justin.chen@broadcom.com>
Cc: f.fainelli@gmail.com
Cc: linux-mips@linux-mips.org
Cc: bcm-kernel-feedback-list@broadcom.com
Patchwork: https://patchwork.linux-mips.org/patch/14650/


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