x86/amd: Fix L1i and L2 cache sharing information for AMD family 15h processors

For L1 instruction cache and L2 cache the shared CPU information
is wrong. On current AMD family 15h CPUs those caches are shared
between both cores of a compute unit.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=42607

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Petkov Borislav <Borislav.Petkov@amd.com>
Cc: Dave Jones <davej@redhat.com>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/20120208195229.GA17523@alberich.amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>