sandbox: virtio: Disable the sandbox virtio blk device

This is not implemented so cannot actually be used to read blocks.
Disable it until it is implemented, to avoid causing a hang with EFI,
which probes every available BLK device.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
Issue: https://source.denx.de/u-boot/u-boot/-/issues/37
diff --git a/arch/Kconfig b/arch/Kconfig
index 8f1f466..c39efb4 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -212,7 +212,8 @@
 	imply VIRTIO_MMIO
 	imply VIRTIO_PCI
 	imply VIRTIO_SANDBOX
-	imply VIRTIO_BLK
+	# Re-enable this when fully implemented
+	# imply VIRTIO_BLK
 	imply VIRTIO_NET
 	imply DM_SOUND
 	imply PCI_SANDBOX_EP