MIPS: ralink: Fix invalid tick count

The current code adds the delta twice, which is obviously wrong.
Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11443/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/ralink/cevt-rt3352.c

@@ -48,7 +48,7 @@ static int systick_next_event(unsigned long delta,
 	sdev = container_of(evt, struct systick_device, dev);
 	count = ioread32(sdev->membase + SYSTICK_COUNT);
 	count = (count + delta) % SYSTICK_FREQ;
-	iowrite32(count + delta, sdev->membase + SYSTICK_COMPARE);
+	iowrite32(count, sdev->membase + SYSTICK_COMPARE);
 
 	return 0;
 }