x86: hpet: Fix copy-and-paste mistake in earlier change

This fixes an oversight in 396e2c6f
("x86: Clear HPET configuration registers on startup"), noticed by
Thomas Gleixner.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/4FBF7DA902000078000861EE@nat28.tlf.novell.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>