Sequential accesses to non-existent memory must be synchronized,
at least on G2 cores.

This fixes get_ram_size() problems on MPC5200 Rev. B boards.
diff --git a/include/common.h b/include/common.h
index 349d5cf..ac78d1c 100644
--- a/include/common.h
+++ b/include/common.h
@@ -270,7 +270,7 @@
 void	jumptable_init(void);
 
 /* common/memsize.c */
-int	get_ram_size  (volatile long *, long);
+long	get_ram_size  (volatile long *, long);
 
 /* $(BOARD)/$(BOARD).c */
 void	reset_phy     (void);