spl: Create a function to init spl_load_info

Rather than having every caller set this up individually, create a
common init function. This allows new fields to be added without the
risk of them being left uninited.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Michael Trimarchi <michael@amarulasolutions.com>
diff --git a/drivers/usb/gadget/f_sdp.c b/drivers/usb/gadget/f_sdp.c
index 514c097..5d62eb4 100644
--- a/drivers/usb/gadget/f_sdp.c
+++ b/drivers/usb/gadget/f_sdp.c
@@ -842,9 +842,7 @@
 				struct spl_load_info load;
 
 				debug("Found FIT\n");
-				load.priv = header;
-				spl_set_bl_len(&load, 1);
-				load.read = sdp_load_read;
+				spl_load_init(&load, sdp_load_read, header, 1);
 				spl_load_simple_fit(spl_image, &load, 0,
 						    header);
 
@@ -855,9 +853,7 @@
 			    valid_container_hdr((void *)header)) {
 				struct spl_load_info load;
 
-				load.priv = header;
-				spl_set_bl_len(&load, 1);
-				load.read = sdp_load_read;
+				spl_load_init(&load, sdp_load_read, header, 1);
 				spl_load_imx_container(spl_image, &load, 0);
 				return SDP_EXIT;
 			}