nios2: Memory management

This patch contains the initialisation of the memory blocks, MMU
attributes and the memory map.

Signed-off-by: Ley Foon Tan <lftan@altera.com>

diff --cc arch/nios2/include/asm/mmu.h
Simple merge

diff --cc arch/nios2/include/asm/page.h
Simple merge

diff --cc arch/nios2/include/asm/uaccess.h
Simple merge

diff --cc arch/nios2/mm/init.c
Simple merge

diff --cc arch/nios2/mm/uaccess.c
Simple merge