Add the ralink signature, will use it later

SVN-Revision: 8702

tools/firmware-utils/src/csysimg.h

@@ -58,6 +58,7 @@
 #define SIG_PS1205UWg	"4000"
 #define SIG_PS3205U	"5010"
 #define SIG_PS3205UWg	"5011"
+#define SIG_RALINK	"RNRA"
 
 #define SIG_H2BR4	SIG_BR6524K
 #define SIG_H2WR54G	SIG_BR6524WG