kernel: Decide whether to use simple or affine scheduler

Simple scheduler is used when we do not have to worry about cache affinity
(i.e. single core with or without SMT, multicore with all cache levels
shared).

When we replace gSchedulerLock with more fine grained locking affine
scheduler should also be chosen when logical CPU count is high (regardless
of cache).

headers/private/kernel/cpu.h

@@ -76,6 +76,7 @@ typedef struct cpu_ent {
 
 //extern cpu_ent gCPU[MAX_BOOT_CPUS];
 extern cpu_ent gCPU[];
+extern uint32 gCPUCacheLevelCount;
 
 
 #ifdef __cplusplus