spl: Update fat functions to take an spl_image parameter

Update the fat loader to avoid using the spl_image global variable.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/include/spl.h b/include/spl.h
index 5ef9ae6..1f4f4e5 100644
--- a/include/spl.h
+++ b/include/spl.h
@@ -184,9 +184,11 @@
 	}
 
 /* SPL FAT image functions */
-int spl_load_image_fat(struct blk_desc *block_dev, int partition,
+int spl_load_image_fat(struct spl_image_info *spl_image,
+		       struct blk_desc *block_dev, int partition,
 		       const char *filename);
-int spl_load_image_fat_os(struct blk_desc *block_dev, int partition);
+int spl_load_image_fat_os(struct spl_image_info *spl_image,
+			  struct blk_desc *block_dev, int partition);
 
 void __noreturn jump_to_image_no_args(struct spl_image_info *spl_image);