binman: Add a way to read the ROM offset

Provide a function to read the ROM offset so that we can store the value
in one place and clients don't need to store it themselves after calling
binman_set_rom_offset().

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/binman.c b/lib/binman.c
index 7a8ad62..79e497f 100644
--- a/lib/binman.c
+++ b/lib/binman.c
@@ -43,7 +43,7 @@
 
 	ret = ofnode_read_u32(node, "image-pos", &entry->image_pos);
 	if (ret)
-		return log_msg_ret("import-pos", ret);
+		return log_msg_ret("image-pos", ret);
 	ret = ofnode_read_u32(node, "size", &entry->size);
 	if (ret)
 		return log_msg_ret("size", ret);
@@ -83,6 +83,11 @@
 	binman->rom_offset = rom_offset;
 }
 
+int binman_get_rom_offset(void)
+{
+	return binman->rom_offset;
+}
+
 int binman_init(void)
 {
 	binman = malloc(sizeof(struct binman_info));