cpuidle: lpm-levels: Only cancel the bias timer when it's used

The bias timer is only started when WFI is used, so we only need to
try and cancel it after leaving WFI.

Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>

drivers/cpuidle/lpm-levels.c

@@ -1419,6 +1419,7 @@ exit:
 		clusttimer_cancel();
 	}
 	if (cpu->bias) {
+                if (!idx)
 			biastimer_cancel();
 		cpu->bias = 0;
 	}