x86: HPET: read from HPET_Tn_CMP() not HPET_T0_CMP

In hpet_next_event() we check that the value we just wrote to
HPET_Tn_CMP(timer) has reached the chip. Currently, we're checking that
the value we wrote to HPET_Tn_CMP(timer) is in HPET_T0_CMP, which, if
timer is anything other than timer 0, is likely to fail.
Signed-off-by: NMatt Fleming <mjf@gentoo.org>
Cc: mingo@elte.hu
Cc: venkatesh.pallipadi@intel.com
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/hpet.c

@@ -322,7 +322,7 @@ static int hpet_next_event(unsigned long delta,
 	 * what we wrote hit the chip before we compare it to the
 	 * counter.
 	 */
-	WARN_ON_ONCE((u32)hpet_readl(HPET_T0_CMP) != cnt);
+	WARN_ON_ONCE((u32)hpet_readl(HPET_Tn_CMP(timer)) != cnt);
 
 	return (s32)((u32)hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0;
 }