parisc: add flexible mmap memory layout support

Add support for the flexible mmap memory layout (as described in
http://lwn.net/Articles/91829). This is especially very interesting on
parisc since we currently only support 32bit userspace (even with a
64bit Linux kernel).

Signed-off-by: Helge Deller <deller@gmx.de>

diff --cc arch/parisc/include/asm/elf.h
Simple merge

diff --cc arch/parisc/include/asm/pgtable.h
Simple merge

diff --cc arch/parisc/include/asm/processor.h
Simple merge

diff --cc arch/parisc/include/asm/thread_info.h
Simple merge

diff --cc arch/parisc/kernel/process.c
Simple merge

diff --cc arch/parisc/kernel/sys_parisc.c
Simple merge