Fix mysql-test/suite/percona missing from `make dist`.

mysql-test/Makefile.am

@@ -104,6 +104,7 @@ TEST_DIRS = t r include std_data std_data/parts collections \
 	suite/pbxt/t suite/pbxt/r \
 	suite/innodb suite/innodb/t suite/innodb/r suite/innodb/include \
 	suite/innodb_plugin suite/innodb_plugin/t suite/innodb_plugin/r suite/innodb_plugin/include \
+	suite/percona \
 	suite/engines suite/engines/funcs suite/engines/iuds suite/engines/rr_trx \
 	suite/engines/funcs/r suite/engines/funcs/t suite/engines/iuds/r \
 	suite/engines/iuds/t suite/engines/rr_trx/include suite/engines/rr_trx/r \