x86: cleanup div_sc() usage

Remove the magic number in the third argment of div_sc().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 36652ea..9007f9e 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -218,7 +218,7 @@
 	hpet_freq = 1000000000000000ULL;
 	do_div(hpet_freq, hpet_period);
 	hpet_clockevent.mult = div_sc((unsigned long) hpet_freq,
-				      NSEC_PER_SEC, 32);
+				      NSEC_PER_SEC, hpet_clockevent.shift);
 	/* Calculate the min / max delta */
 	hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF,
 							   &hpet_clockevent);