UPSTREAM: timer: Export destroy_hrtimer_on_stack()

hrtimer_init_on_stack() needs a matching call to
destroy_hrtimer_on_stack(), so both need to be exported.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit c08376ac97cb202ec65320f3d90d5c4c5e2adb0b)
[astrachan: Fixes i386-allmodconfig build failure in vsoc.ko noticed
 by 01.org kbuild-all project building kernel/msm]
Bug: 78036828
Change-Id: If4d5c466255019322ea21ef38ee5b1b382cce969
Signed-off-by: Alistair Strachan <astrachan@google.com>