KVM: arm64: Use kvm_vcpu_has_feature() directly for struct kvm

KVM: arm64: Use kvm_vcpu_has_feature() directly for struct kvm

Now that we have introduced kvm_vcpu_has_feature(), use it in the
remaining code that checks for features in struct kvm, instead of
using the __vcpu_has_feature() helper.

No functional change intended.

Suggested-by: Quentin Perret <qperret@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20241216105057.579031-18-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>