KVM: arm/arm64: No need to zero CNTVOFF in kvm_timer_vcpu_put() for VHE

In AArch64/AArch32, the virtual counter uses a fixed virtual offset
of zero in the following situations as per ARMv8 specifications:

1) HCR_EL2.E2H is 1, and CNTVCT_EL0/CNTVCT are read from EL2.
2) HCR_EL2.{E2H, TGE} is {1, 1}, and either:
   — CNTVCT_EL0 is read from Non-secure EL0 or EL2.
   — CNTVCT is read from Non-secure EL0.

So, no need to zero CNTVOFF_EL2/CNTVOFF for VHE case.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>