evtstrm and cpuid cann't be controlled by VMM:
1. evtstrm: The generic timer is configured to generate events at a
frequency of approximately 100KHz. It's controlled by the linux
kernel config CONFIG_ARM_ARCH_TIMER_EVTSTREAM.
2. cpuid: EL0 access to certain ID registers is available. It's always
set by linux kernel after 77c97b4ee2129 ("arm64: cpufeature: Expose
CPUID registers by emulation").
However, they are exposed by getauxval() and /proc/cpuinfo. Hence,
let's report and ignore the CPU features if someone set them.
Signed-off-by: Peng Liang <liangpeng10@huawei.com>