arm64: KVM: Move kvm_call_hyp back to its original localtion

In order to reduce the risk of a bad merge, let's move the new
kvm_call_hyp back to its original location in the file. This has
zero impact from a code point of view.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>