clocksource: Use a plain u64 instead of cycle_t

There is no point in having an extra type for extra confusion. u64 is
unambiguous.

Conversion was done with the following coccinelle script:

@rem@
@@
-typedef u64 cycle_t;

@fix@
typedef cycle_t;
@@
-cycle_t
+u64

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
index 25c2366..ba87a27 100644
--- a/arch/um/kernel/time.c
+++ b/arch/um/kernel/time.c
@@ -83,7 +83,7 @@
 	return IRQ_HANDLED;
 }
 
-static cycle_t timer_read(struct clocksource *cs)
+static u64 timer_read(struct clocksource *cs)
 {
 	return os_nsecs() / TIMER_MULTIPLIER;
 }