perf/x86/intel/uncore: Make UNCORE_PMU_HRTIMER_INTERVAL 64-bit

i386 allmodconfig:

 arch/x86/kernel/cpu/perf_event_intel_uncore.c: In function 'uncore_pmu_hrtimer':
 arch/x86/kernel/cpu/perf_event_intel_uncore.c:728: warning: integer overflow in expression
 arch/x86/kernel/cpu/perf_event_intel_uncore.c: In function 'uncore_pmu_start_hrtimer':
 arch/x86/kernel/cpu/perf_event_intel_uncore.c:735: warning: integer overflow in expression

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Zheng Yan <zheng.z.yan@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-h84qlqj02zrojmxxybzmy9hi@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>