drm/msm/submit: Move copy_from_user ahead of locking bos

We cannot switch to using obj->resv for locking without first moving all
the copy_from_user() ahead of submit_lock_objects().  Otherwise in the
mm fault path we aquire mm->mmap_sem before obj lock, but in the submit
path the order is reversed.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Signed-off-by: Rob Clark <robdclark@chromium.org>