sparc64: Set up core sibling list correctly for T7.

sparc64: Set up core sibling list correctly for T7.

The important definition of core sibling is that some level of cache is shared.
The prior SPARC notion of socket was defined as highest level of shared cache.
On T7 platforms, the MD record now describes the CPUs that share the physical
socket and this is no longer tied to shared cache. This patch correctly
separates these two concepts.

Before:
[root@ca-sparc30 topology]# cat core_siblings_list
32-63,128-223

After:
[root@ca-sparc30 topology]# cat core_siblings_list
32-63

OraBug 22748950

Signed-off-by: Chris Hyser <chris.hyser@oracle.com>