drm/i915: Reject more ioctls for userptr, v2.

There are a couple of ioctl's related to tiling and cache placement,
that make no sense for userptr, reject those:
- i915_gem_set_tiling_ioctl()
    Tiling should always be linear for userptr. Changing placement will
    fail with -ENXIO.
- i915_gem_set_caching_ioctl()
    Userptr memory should always be cached. Changing caching mode will
    fail with -ENXIO.
- i915_gem_set_domain_ioctl()
    Still temporarily allowed to work as intended, it's used to check
    userptr validity. With the reworked userptr code, it will keep
    working for this usecase.

This plus the previous changes have been tested against beignet
by using its own unit tests, and intel-video-compute by using
piglit's opencl tests.

Changes since v1:
- set_domain was apparently used in iris for checking userptr validity,
  keep it working as intended.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Acked-by: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-14-maarten.lankhorst@linux.intel.com