KVM: arm/arm64: Update the physical timer interrupt level

Now that we maintain the EL1 physical timer register states of VMs,
update the physical timer interrupt level along with the virtual one.

Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>