MIPS: Netlogic: Support for multi-chip configuration

Upto 4 Netlogic XLP SoCs can be connected over ICI links to form a
coherent multi-node system.  Each SoC has its own set of on-chip
devices including PIC.  To support this, add a per SoC stucture and
use it for the PIC and SYS block addresses instead of using global
variables.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4469
Signed-off-by: John Crispin <blogic@openwrt.org>