spl: Add a type for the jumper function

This function will be used by the relocating jumper too, so add a
typedef to the header file to avoid mismatches.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/spl/spl.c b/common/spl/spl.c
index ad31a2f..09e6dc2 100644
--- a/common/spl/spl.c
+++ b/common/spl/spl.c
@@ -671,8 +671,7 @@
 		BOOT_DEVICE_NONE,
 		BOOT_DEVICE_NONE,
 	};
-	typedef void __noreturn (*jump_to_image_t)(struct spl_image_info *);
-	jump_to_image_t jump_to_image = &jump_to_image_no_args;
+	spl_jump_to_image_t jump_to_image = &jump_to_image_no_args;
 	struct spl_image_info spl_image;
 	int ret, os;
 
diff --git a/include/spl.h b/include/spl.h
index 781e5a2..488adbe 100644
--- a/include/spl.h
+++ b/include/spl.h
@@ -292,6 +292,9 @@
 #endif
 };
 
+/* function to jump to an image from SPL */
+typedef void __noreturn (*spl_jump_to_image_t)(struct spl_image_info *);
+
 static inline void *spl_image_fdt_addr(struct spl_image_info *info)
 {
 #if CONFIG_IS_ENABLED(LOAD_FIT) || CONFIG_IS_ENABLED(LOAD_FIT_FULL)