panfrost: Move pool routines to common code

We finally have it decoupled from Galliumisms (and OpenGLisms, indeed)
so we can share the file.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5794>
11 files changed