riscv: Move virtio scan to board_late_init()

When virtio_init() gets called from board_init() PCI isn't ready. Thus,
virtio-over-PCI (e.g. network interfaces) devices can't be detected and
used without additional `virtio scan` scan in the shell or a script.

Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index d70c7e3..7e20ef6 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -22,6 +22,7 @@
 
 config TARGET_QEMU_VIRT
 	bool "Support QEMU Virt Board"
+	select BOARD_LATE_INIT
 
 config TARGET_SIFIVE_UNLEASHED
 	bool "Support SiFive Unleashed Board"
diff --git a/board/emulation/qemu-riscv/qemu-riscv.c b/board/emulation/qemu-riscv/qemu-riscv.c
index 181abbb..173245b 100644
--- a/board/emulation/qemu-riscv/qemu-riscv.c
+++ b/board/emulation/qemu-riscv/qemu-riscv.c
@@ -31,12 +31,6 @@
 
 int board_init(void)
 {
-	/*
-	 * Make sure virtio bus is enumerated so that peripherals
-	 * on the virtio bus can be discovered by their drivers
-	 */
-	virtio_init();
-
 	return 0;
 }
 
@@ -46,6 +40,12 @@
 	if (CONFIG_IS_ENABLED(USB_KEYBOARD))
 		usb_init();
 
+	/*
+	 * Make sure virtio bus is enumerated so that peripherals
+	 * on the virtio bus can be discovered by their drivers
+	 */
+	virtio_init();
+
 	return 0;
 }