vread_hpet() uses "0xf0" as the offset of the hpet counter. To
clarify the meaning of this code, it should use symbolic name,
HPET_COUNTER, instead.
Signed-off-by: NSatoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>