Silent drivers/char/hpet.c build warnings on i386

Following patch silents;

...
drivers/char/hpet.c:72: warning: 'clocksource_hpet' defined but not used
drivers/char/hpet.c:81: warning: 'hpet_clocksource' defined but not used
...

build warnings on i386, they appeared after commit 3b2b64fd

Signed-off-by: S.Çağlar Onur <caglar@pardus.org.tr>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
--
 drivers/char/hpet.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)