ANDROID: GKI: arm64: reserve space in cpu_hwcaps and cpu_hwcap_keys arrays

Since cpu_hwcaps and cpu_hwcap_keys are exported symbols, reserve
space in them for any future cpu capabilities or erratas.

Bug: 151154716
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I35930dd52d98817831d812f35560a2605804a553