x86: mark get_cpu_leaves() with __cpuinit annotation

Impact: fix section mismatch warning

Commit b2bb8554 ("x86: Remove cpumask games
in x86/kernel/cpu/intel_cacheinfo.c") introduced get_cpu_leaves(), which
references __cpuinit cpuid4_cache_lookup().

Mark get_cpu_leaves() with a __cpuinit annotation.

Signed-off-by: Sergio Luis <sergio@larces.uece.br>
Signed-off-by: Ingo Molnar <mingo@elte.hu>