MODSIGN: Use utf8 strings in signer's name in autogenerated X.509 certs

Place an indication that the certificate should use utf8 strings into the
x509.genkey template generated by kernel/Makefile.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

kernel/Makefile

@@ -194,6 +194,7 @@ x509.genkey:
 	@echo >>x509.genkey "default_bits = 4096"
 	@echo >>x509.genkey "distinguished_name = req_distinguished_name"
 	@echo >>x509.genkey "prompt = no"
+	@echo >>x509.genkey "string_mask = utf8only"
 	@echo >>x509.genkey "x509_extensions = myexts"
 	@echo >>x509.genkey
 	@echo >>x509.genkey "[ req_distinguished_name ]"