iris: Store intel_device_info in iris_bufmgr

iris: Store intel_device_info in iris_bufmgr

We can have multiple pipe_screen but only one iris_bufmgr per device.
So better to store intel_device_info into the shared iris_bufmgr and
save some memory.
Also in future patches iris_bufmgr will make more use of
intel_device_info.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19650>