arm64: KVM: Remove duplicating init code for setting VMID

By now both VHE and non-VHE initialisation sequences query supported
VMID size. Lets keep only single instance of this code under
init_common_resources().

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>