[or32]: Remove bits/mman.h
[or32]: Remove bits/mman.h

We should be using the generic version which will be kept nicely in sync
with the upstream Linux asm-generic/mman.h flags.

skristiansson/uClibc-or1k,skristiansson/uClibc-or1k,skristiansson/uClibc-or1k,skristiansson/uClibc-or1k