Add support for Linux-like kallsysms

The kernel stores address<->symbol names in it so things can be decoded at
runtime.  Do it in U-Boot, and we get nice symbol decoding when crashing.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

include/common.h

@@ -300,6 +300,9 @@ int	misc_init_r   (void);
 /* common/exports.c */
 void	jumptable_init(void);
 
+/* common/kallsysm.c */
+const char *symbol_lookup(unsigned long addr, unsigned long *caddr);
+
 /* api/api.c */
 void	api_init (void);