Include virtio DRM drivers in hostonly initramfs

The code in 50drm which tries to include all DRM drivers for
hardware attached to the system did not look for virtio devices.
So if the system is a VM using the 'virtio' graphics adapter,
the 'virtio-gpu' module which should be included is not. This
extends the code to also look for virtio devices.

https://bugzilla.redhat.com/show_bug.cgi?id=1593028

Signed-off-by: Adam Williamson <awilliam@redhat.com>

modules.d/50drm/module-setup.sh

@@ -31,7 +31,7 @@ installkernel() {
     # as we could e.g. be in the installer; nokmsboot boot parameter will disable
     # loading of the driver if needed
     if [[ $hostonly ]]; then
-        for i in /sys/bus/{pci/devices,soc/devices/soc?}/*/modalias; do
+        for i in /sys/bus/{pci/devices,virtio/devices,soc/devices/soc?}/*/modalias; do
             [[ -e $i ]] || continue
             if hostonly="" dracut_instmods --silent -s "drm_crtc_init" -S "iw_handler_get_spy" $(<$i); then
                 if strstr "$(modinfo -F filename $(<$i) 2>/dev/null)" radeon.ko; then