mips: SoC or board specific override of flush_dcache_range()

Hello Daniel et. all,

We have a need to override what is done inside arch/mips/lib/cache.c::flush_dcache_range() for our SoC/board.

Easiest approach seems to be making the function __weak upstream. i.e.

-void flush_dcache_range(ulong start_addr, ulong stop) +void __weak flush_dcache_range(ulong start_addr, ulong stop)

thoughts?

Thanks -AN