drm/xe/uapi: Kill VM_MADVISE IOCTL

drm/xe/uapi: Kill VM_MADVISE IOCTL

Remove unused IOCTL.
Without any userspace using it we need to remove before we
can be accepted upstream.

At this point we are breaking the compatibility for good,
so we don't need to break when we are in-tree. So, let's
also use this breakage to sort out the IOCTL entries and
fix all the small indentation and line issues.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>