panfrost: Move BO meta-data out of panfrost_bo

panfrost: Move BO meta-data out of panfrost_bo

That's what most (all?) implementation seem to do, and my understanding
is that a BO is just a bunch of memory that can be used for anything GPU
related, not only texture/FB resources.

Let's move those meta data in panfrost_resource so we can use
panfrost_bo for all kind of memory allocation and make BO allocation
more consistent.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>