[ruby/psych] Update autoconf files bundled with yaml-2.5

ruby/psych@e28f17ac18

Author: nobu

ext/psych/extlibs

@@ -1,7 +1,11 @@
 ver = 0.2.5
+pkg = yaml-$(ver)
 
-https://github.com/yaml/libyaml/releases/download/$(ver)/yaml-$(ver).tar.gz \
+https://github.com/yaml/libyaml/releases/download/$(ver)/$(pkg).tar.gz \
 	rmd160:cc175ed640046722fb7790de828002633407b6b9 \
 	sha256:c642ae9b75fee120b2d96c712538bd2cf283228d2337df2cf2988e3c02678ef4 \
 	sha512:dadd7d8e0d88b5ebab005e5d521d56d541580198aa497370966b98c904586e642a1cd4f3881094eb57624f218d50db77417bbfd0ffdce50340f011e35e8c4c02 \
 	#
+
+$(pkg)/config/config.guess -> /tool/config.guess
+$(pkg)/config/config.sub -> /tool/config.sub