spl: introduce function prototypes

Introduce function prototypes for board_spl_fit_size_align and
board_spl_fit_post_load

Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/include/spl.h b/include/spl.h
index 3f4b92c..c82f2fd 100644
--- a/include/spl.h
+++ b/include/spl.h
@@ -354,6 +354,18 @@
 void board_return_to_bootrom(void);
 
 /**
+ * board_spl_fit_post_load - allow process images after loading finished
+ *
+ */
+void board_spl_fit_post_load(ulong load_addr, size_t length);
+
+/**
+ * board_spl_fit_size_align - specific size align before processing payload
+ *
+ */
+ulong board_spl_fit_size_align(ulong size);
+
+/**
  * spl_perform_fixups() - arch/board-specific callback before processing
  *                        the boot-payload
  */