mm: convert vma->vm_flags to 64bit

[KOSAKI Motohiro]

Benjamin, Hugh, I hope to add your S-O-B to this one because you are original author. 
Can I do?

Paul, Russell, This patch modifies arm and sh code a bit. I don't think
they are risky change. but I'm really glad if you see it.


Note: I confirmed x86, power and nommu-arm cross compiler build and
I've got no warning/error.