kvm: arm64: make ID_AA64PFR0_EL1 configurable

hulk inclusion
category: feature
bugzilla: 48052
CVE: NA

------------------------------

Since 23711a5e ("KVM: arm64: Allow setting of ID_AA64PFR0_EL1.CSV2
from userspace"), ID_AA64PFR0_EL1 uses a separate set_user callback.  We
should remove some check in the callback to make ID_AA64PFR0_EL1
configurable.

Signed-off-by: Peng Liang <liangpeng10@huawei.com>
Reviewed-by: Zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>