panvk: expose KHR_dedicated_allocation

Caterina already implemented this in ed64fa03 ("panvk: never prefer or
require dedicated allocation for buffers") and dbdaefb6 ("panvk: never
require dedicated allocation for images"), so let's flip the switch.

We pass 4505 of the CTS tests, and fail a single one. Let's mark that
one as an expected failure and move on for now.

Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <!32466>