arm64: cpufeature: add HWCAP for FEAT_AFP

stable inclusion
from stable-v5.10.105
commit 162aa002ec1a78e91cf2f0b8e7450e2770b2941f
bugzilla: https://gitee.com/openeuler/kernel/issues/I5702G

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=162aa002ec1a78e91cf2f0b8e7450e2770b2941f



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

commit 5c13f042 upstream.

Add a new HWCAP to detect the Alternate Floating-point Behaviour
feature (FEAT_AFP), introduced in Armv8.7.

Also expose this to userspace in the ID_AA64MMFR1_EL1 feature register.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Will Deacon <will@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211210165432.8106-2-joey.gouly@arm.com


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:
	arch/arm64/include/asm/sysreg.h

Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>