KVM: arm64: Introduce vcpu_sve_vq() helper

mainline inclusion
from mainline-v5.13-rc1
commit 468f3477
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8E73O
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=468f3477ef8bda1beeb91dd7f423c9bc248ac39d



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The KVM code contains a number of "sve_vq_from_vl(vcpu->arch.sve_max_vl)"
instances, and we are about to add more.

Introduce vcpu_sve_vq() as a shorthand for this expression.

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Conflicts:
       correct undef function in switch.h
Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>