blk: Rename if_type to uclass_id

Use the word 'uclass' instead of 'if_type' to complete the conversion.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/virtio/virtio_blk.c b/drivers/virtio/virtio_blk.c
index 9710b79..30cfc56 100644
--- a/drivers/virtio/virtio_blk.c
+++ b/drivers/virtio/virtio_blk.c
@@ -75,7 +75,7 @@
 	struct blk_desc *desc = dev_get_uclass_plat(dev);
 	int devnum;
 
-	desc->if_type = UCLASS_VIRTIO;
+	desc->uclass_id = UCLASS_VIRTIO;
 	/*
 	 * Initialize the devnum to -ENODEV. This is to make sure that
 	 * blk_next_free_devnum() works as expected, since the default