drm/v3d: Drop the "dev" argument to lock/unlock of BO reservations.

They were unused, as Dave Emett noticed in TFU review.

Signed-off-by: Eric Anholt <eric@anholt.net>
Cc: Dave Emett <david.emett@broadcom.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181128230927.10951-2-eric@anholt.net


Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>