arm64: Add a capability for FEAT_ECV

mainline inclusion
from mainline-v5.16-rc1
commit fdf86598
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4QCBG


CVE: NA

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

Add a new capability to detect the Enhanced Counter Virtualization
feature (FEAT_ECV).

Reviewed-by: Oliver Upton <oupton@google.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-15-maz@kernel.org


Signed-off-by: Will Deacon <will@kernel.org>

 Conflicts:
	arch/arm64/tools/cpucaps
[ignore modification in 'arch/arm64/tools/cpucaps' because we don't have
this file. Add the modification in arch/arm64/include/asm/cpucaps.h]
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>