MIPS: Allow __cpu_number_map to be larger than NR_CPUS

In systems where the CPU id space is sparse, this allows a smaller
NR_CPUS to be chosen, thus keeping internal data structures smaller.

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Carlos Munoz <cmunoz@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17388/
[jhogan@kernel.org: Add depends on SMP to fix
 "warning: symbol value '' invalid for MIPS_NR_CPU_NR_MAP"]
Signed-off-by: James Hogan <jhogan@kernel.org>

arch/mips/include/asm/smp.h

@@ -29,7 +29,7 @@ extern cpumask_t cpu_foreign_map[];
 
 /* Map from cpu id to sequential logical cpu number.  This will only
    not be idempotent when cpus failed to come on-line.	*/
-extern int __cpu_number_map[NR_CPUS];
+extern int __cpu_number_map[CONFIG_MIPS_NR_CPU_NR_MAP];
 #define cpu_number_map(cpu)  __cpu_number_map[cpu]
 
 /* The reverse map from sequential logical cpu number to cpu id.  */