Update the vcpu id type as uint16_t for vm_create_vcpu, this
keeps alignment with the updates for the structure acrn_create_vcpu
used by hcall_create_vcpu in the hypervisor.
In the device model, the caller is responsible for vcpu id type
conversion; vcpu id type is uint16_t for external interface in the
current implement.
Signed-off-by: Xiangyang Wu <xiangyang.wu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>