KVM: arm/arm64: disable preemption when calling smp_call_function_many

Preemption must be disabled when calling smp_call_function_many

Reported-by:  <bartosz.wawrzyniak@tieto.com>
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>