MIPS: Netlogic: Mark Netlogic chips as SMT capable

MIPS: Netlogic: Mark Netlogic chips as SMT capable

Netlogic XLR chip has multiple cores. Each core includes four integrated
hardware threads, and they share L1 data and instruction caches.

If the chip is marked to be SMT capable, scheduler then could do more, say,
idle load balancing.

Changes are now confined only to the code of XLR, and hardware is probed
to get core ID for correct setup.

[jayachandranc: simplified and adapted for new merged XLR/XLP code]

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Jayachandran C <jayachandranc@netlogicmicro.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2972/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>