x86: free_cache_attributes() section fix

free_cache_attributes() must be __cpuinit since it calls the
__cpuinit cache_remove_shared_cpu_map().

This patch fixes the following section mismatch reported by
Chris Clayton:

 ...
 WARNING: vmlinux.o(.text+0x90b6): Section mismatch: reference to .init.text:cache_remove_shared_cpu_map (between 'free_cache_attributes' and 'show_level')
 ...

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>