msm: kgsl: Don't make assumptions about VMA regions

We cannot assume that a VMA region created as a result of an mmap
belongs exclusively to us.  Allow the user to pass the size of
the vmalloc region through the 'gpuaddr' member of the ioctl
struct and do strict checking on the returned vma to make sure
it is valid.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
1 file changed