sched: add SCHED_IDLE policy

this patch adds the SCHED_IDLE policy to sched.h.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

include/linux/sched.h

@@ -34,6 +34,8 @@
 #define SCHED_FIFO		1
 #define SCHED_RR		2
 #define SCHED_BATCH		3
+/* SCHED_ISO: reserved but not implemented yet */
+#define SCHED_IDLE		5
 
 #ifdef __KERNEL__