bhyve: add ioctl to get acpi resources of an acpi device

[corvink]

Summary

For passthru of ACPI devices like a TPM we need to get the current
resources (CRS) used by the device. Add an ioctl to query that data.

Note: See https://github.com/Beckhoff/freebsd-src/commits/phab/corvink/vm_get_acpi_device_info

[corvink]

This patch was required for my TPM passthrough patch (D32961). I'll change the TPM passthrough patch in the future. After that, this patch won't be required any more.