GRU Driver: driver initialization, file & vma ops

This file contains the functions for initializing the driver, handling
file & vma operations and for processing IOCTL requests from the user.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>