sched_clock: Remove sched_clock_func() hook

Nobody is using sched_clock_func() anymore now that sched_clock
supports up to 64 bits. Remove the hook so that new code only
uses sched_clock_register().

Signed-off-by: Stephen Boyd <[e-mail]>
Signed-off-by: John Stultz <[e-mail]>

include/linux/sched_clock.h

···
 extern void sched_clock_register(u64 (*read)(void), int bits,
 				 unsigned long rate);
 
-extern unsigned long long (*sched_clock_func)(void);
-
 #endif

kernel/time/sched_clock.c

···
 	return (cyc * mult) >> shift;
 }
 
-static unsigned long long notrace sched_clock_32(void)
+unsigned long long notrace sched_clock(void)
 {
 	u64 epoch_ns;
 	u64 epoch_cyc;
···
 {
 	read_sched_clock_32 = read;
 	sched_clock_register(read_sched_clock_32_wrapper, bits, rate);
-}
-
-unsigned long long __read_mostly (*sched_clock_func)(void) = sched_clock_32;
-
-unsigned long long notrace sched_clock(void)
-{
-	return sched_clock_func();
 }
 
 void __init sched_clock_postinit(void)