Fix PCI device ID for virtio-rnd (from bhyve)

[adaugherity]

FreeBSD bhyve commit: https://svnweb.freebsd.org/base?view=revision&revision=311702 From that commit message:

This prevented the device from attaching with a Windows guest (most other guests use the device type for matching).

The corrected ID also matches the PCI ID Repository.

I haven't tested Windows, but Linux and OpenBSD guests do load the driver correctly, albeit with the PCI device identified incorrectly as the memory ballooning device. I'm using -s 5,virtio-rnd for these VMs.

Before - Linux lspci:

00:05.0 Network and computing encryption device: Red Hat, Inc. Virtio memory balloon

Before - OpenBSD dmesg and pcidump:

virtio1 at pci0 dev 5 function 0 "Qumranet Virtio Memory Balloon" rev 0x00
viornd0 at virtio1
# pcidump
 0:5:0: Qumranet Virtio Memory Balloon

With the fix, everything is correctly identified and virtio-rnd still works (at least my Linux VM gets new random data each time I run dd if=/dev/hwrng count=1 | hexdump -C).

After:

# Linux lspci
00:05.0 Network and computing encryption device: Red Hat, Inc. Virtio RNG
# OpenBSD dmesg
virtio1 at pci0 dev 5 function 0 "Qumranet Virtio RNG" rev 0x00
viornd0 at virtio1
# OpenBSD pcidump
 0:5:0: Qumranet Virtio RNG