intel: Store the aperture size in devinfo.

intel: Store the aperture size in devinfo.

We will later use the devinfo from iris_bufmgr, where we don't have
access to the screen pointer. And since we are moving it, we can reuse
it in Anv and i965.

v2: return error code and check for it on Anv (Lionel).
v3: Remove anv_gem_get_aperture() from anv_private.h and stubs (Lionel).

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5043>