drivers: perf: use us_to_ktime() where appropriate

The arm_ccn_pmu_poll_period_us are more suitable for using
the us_to_ktime(). This can make the code more concise and
enhance readability.

Signed-off-by: Xichao Zhao <[e-mail]>
Acked-by: Mark Rutland <[e-mail]>
Signed-off-by: Will Deacon <[e-mail]>

drivers/perf/arm-ccn.c

···
 
 static ktime_t arm_ccn_pmu_timer_period(void)
 {
-	return ns_to_ktime((u64)arm_ccn_pmu_poll_period_us * 1000);
+	return us_to_ktime((u64)arm_ccn_pmu_poll_period_us);
 }