Added the match table and pointers for ACPI probing to the driver.

This uses the same identifier for virt devices as being used for qemu
ARM64 ACPI support.

http://git.linaro.org/people/shannon.zhao/qemu.git/commit/d0bf1955a3ecbab4b51d46f8c5dda02b7e14a17eSigned-off-by: Graeme Gregory <graeme.gregory@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>