qemu-riscv: enable VIRTIO_PCI

libvirt v.5.3.0 with QEMU 4.0.0 or above uses PCI automatically and
thus devices (network, storage, etc) are connected via PCI.

Signed-off-by: David Abdurachmanov <david.abdurachmanov@sifive.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/board/emulation/qemu-riscv/Kconfig b/board/emulation/qemu-riscv/Kconfig
index 7f9a74d..6cc7c31 100644
--- a/board/emulation/qemu-riscv/Kconfig
+++ b/board/emulation/qemu-riscv/Kconfig
@@ -24,6 +24,7 @@
 	imply VIRTIO_MMIO
 	imply VIRTIO_NET
 	imply VIRTIO_BLK
+	imply VIRTIO_PCI
 	imply CMD_PING
 	imply CMD_FS_GENERIC
 	imply DOS_PARTITION