drm/<drivers>: Drop DRM_UNLOCKED from modeset drivers

Just one special case (since i915 lost its ums code, yay):
- radeon: Has slots for the old ums ioctls which don't have
  DRM_UNLOCKED, but all filled with drm_invalid_op. So ok to drop it
  everywhere.

Every other kms driver just has DRM_UNLOCKED for all their ioctls, as
they should.

v2: admgpu happened, include that one too. And i915 lost its UMS
support which means we can change all the i915 ioctls too.

v3: Rebased on top of new vmwgfx DX interface extensions.

v4: Rebase on top of render-node support in exynos.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>