x86: detect and initialize Intel CAT feature

x86: detect and initialize Intel CAT feature

Detect Intel Cache Allocation Technology(CAT) feature and store the
cpuid information for later use. Currently only L3 cache allocation is
supported. The L3 CAT features may vary among sockets so per-socket
feature information is stored. The initialization can happen either at
boot time or when CPU(s) is hot plugged after booting.

Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Use -1 as notifier priority. Fix typos.

Signed-off-by: Jan Beulich <jbeulich@suse.com>