MIPS: mm: BMIPS5000 has inclusive physical caches

When the BMIPS generic cpu-feature-overrides.h file was introduced,
cpu_has_inclusive_caches/MIPS_CPU_INCLUSIVE_CACHES was not set for
BMIPS5000 CPUs. Correct this when we have initialized the MIPS secondary
cache successfully.

Fixes: f337967d ("MIPS: BMIPS: Add cpu-feature-overrides.h")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>