Added nios2 target detection in config.sub

git-svn-id: https://svn.pjsip.org/repos/pjproject/trunk@1948 74dad513-b988-da41-8d7b-12977e46ad98

config.sub

@@ -1113,6 +1113,9 @@ case $basic_machine in
 	pmac | pmac-mpw)
 		basic_machine=powerpc-apple
 		;;
+	nios2*)
+		basic_machine=nios2-altera
+		;;
 	*-unknown)
 		# Make sure to match an already-canonicalized machine name.
 		;;